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1007

This is to certify that the
thesis entitled

A BOAT NOISE MEASUREMENT DEVICE FOR LAW
ENFORCEMENT

presented by

CASEY PATRICK MANNING

has been accepted towards fulfillment
of the requirements for the

MS. degree in Mechanical Engineering

 

 

 

 

 

MSU is an Affirmative Action/Equal Opportunity Institution

 

 

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Michigan State
Unlverslty

 

 

 

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PLACE IN RETURN BOX to remove this checkout from your record.
TO AVOID FINES return on or before date due.
MAY BE RECALLED with earlier due date if requested.

 

DATE DUE DATE DUE DATE DUE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2/05 p:/ClRC/DateDue.indd-p.1

A BOAT NOISE MEASUREMENT DEVICE FOR LAW ENFORCEMENT
By

Casey Patrick Manning

A THESIS
Submitted to
Michigan State University

in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE
Department of Mechanical Engineering

2006

ABSTRACT
A BOAT NOISE MEASUREMENT DEVICE FOR LAW ENFORCEMENT
By

Casey Patrick Manning

Boat noise is a serious problem on Michigan lakes. Current Michigan boat noise
laws use the scientific measurement standards SAE J 1970 and SAE 12005 to qualify boat
noise for law enforcement purposes. These standards are very detailed and require a
skilled boat operator and precise conditions in order to be performed correctly. They also
do not measure the noise level of the boat under normal operation. A new method of
enforcing boat noise regulations for boats under normal operation is needed.

A boat noise measurement device was designed to study boat sound propagation
and take into account all applicable errors associated with its measurements. From
understanding sound prOpagation, this device can be used to calculate the minimum
possible noise level at a specific distance from any measured distance. By taking into
account all applicable errors, this device can lead to an effective law enforcement tool.
The device was designed as a complement to the SAE J 34 standard, which measures boat
noise from boats passing by at a known distance.

The data matched the propagation model and agreed with past studies by other
investigators. The results Show the propagation model can yield a minimum possible
noise level underpredicting the SAE J34 level. By emulating the SAE J34 standard the
measurements can be made while the boat is in normal operation, as opposed to
measuring the boats ability to be loud. Conservative error compensation and standard

deviation correction ensures an accurate law enforcement device.

ACKNOWLEDGEMENTS

The author wishes to express his thanks and appreciation to Dr. Clark Radcliffe,
Department of Mechanical Engineering, for his guidance in this project. Also, Mr. Ned
Wickes and the Higgins Lake Property Owners' Association deserve thanks for their time
and support. Thanks to the Michigan Department of Natural Resources and Michigan
Lake and Stream Associations for their generous funding.

Furthermore, special thanks to members of the Torch and Higgins Lake
communities. The time Spent testing loud boats on their waters was a temporary
inconvenience, and their gratitude and patience was very much appreciated. And special
thanks to the Antrim and Roscommon County Sheriff‘s Departments for their time and

help in running our tests smoothly.

iii

TABLE OF CONTENTS

List of Tables ....................................................................................................................... v
List of Figures ................................................................................................................... vii
Key to Symbols and Abbreviations ..................................................................................... x
Problem Statement ............................................................................................................... 1
Boat Noise Standards ........................................................................................................... 3
The SAE J34 Standard ............................................................................................. 5
The ICOMIA 45-98 and ISO 14509 Standards ....................................................... 6
The SAE 11970 and SAE 12005 Standards .............................................................. 8
Special Conditions of Current Boat Noise Standards ........................................................ 10
Sound Propagation ............................................................................................................. 12
Planar Sound Propagation ...................................................................................... 13
Spherical Sound Propagation ................................................................................. 14
Richard Lanpheer's Sound Propagation Study ....................................................... 16
Background Sound Level Measurement and Compensation ............................................. 21
First Boat Noise Measurement Device Prototype ....................................... i. ...................... 24
Current Boat Noise Measurement Device Prototype ......................................................... 28
Testing Results ................................................................................................................... 35
Conclusions ........................................................................................................................ 42
Recommendations for Future Work ................................................................................... 44
Appendices ......................................................................................................................... 45
Appendix A: Weighting Filter and Sampling Time Definitions ............................ 45
Appendix B: The Exponential Time-Average Sound Pressure Level ................... 50
Appendix C: Circuit Schematic and PC Board Layout ......................................... 54
Appendix D: Basic Stamp Program ....................................................................... 58
Appendix E: Field Data ......................................................................................... 71
Appendix F: Correction Calculation Comparison ................................................. 87
Appendix G: Analysis of SAE J34 Distance Acceptability ................................. 103
Works Cited ..................................................................................................................... 105

iv

LIST OF TABLES

Table 1: Comparison of Different Existing Standards ......................................................... 9
Table 2: Standard Deviation of Reproducibility [reproduced from ISO 14509, 2004] ..... 37
Table 3: Weighting Filters and Their Appropriate Ranges Of Use .................................... 47
Table 4: Test #1 Noise Gun Readout ................................................................................. 72
Table 5: Test #2 Noise Gun Readout ................................................................................. 73
Table 6: Test #3 Noise Gun Readout ................................................................................. 74
Table 7: Test #4 Noise Gun Readout ................................................................................. 75
Table 8: Test #5 Noise Gun Readout ................................................................................. 76
Table 9: Test #6 Noise Gun Readout ................................................................................. 77
Table 10: Test #7 Noise Gun Readout ............................................................................... 78
Table 11: Test #8 Noise Gun Readout ............................................................................... 79
Table 12: Test #9 Noise Gun Readout ............................................................................... 80
Table 13: Test #10 Noise Gun Readout ............................................................................. 81
Table 14: Test #11 Noise Gun Readout ............................................................................. 82
Table 15: Test #12 Noise Gun Readout ............................................................................. 83
Table 16: Test #13 Noise Gun Readout ............................................................................. 84
Table 17: Test #14 Noise Gun Readout ............................................................................. 85
Table 18: Test #15 Noise Gun Readout ............................................................................. 86
Table 19: Test #1, Device Corrected SPL Approximation Compared to the Actual

Decimal Calculation ..................................................................................................... 88
Table 20: Test #2, Device Corrected SPL Approximation Compared to the Actual

Decimal Calculation ..................................................................................................... 89
Table 21: Test #3, Device Corrected SPL Approximation Compared to the Actual

Decimal Calculation ..................................................................................................... 90

Table 22: Test #4, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ..................................................................................................... 91

Table 23: Test #5, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ..................................................................................................... 92

Table 24: Test #6, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ..................................................................................................... 93

Table 25: Test #7, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ..................................................................................................... 94

Table 26: Test #8, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ..................................................................................................... 95

Table 27: Test #9, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ..................................................................................................... 96

Table 28: Test #10, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ..................................................................................................... 97

Table 29: Test #1 1, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ..................................................................................................... 98

Table 30: Test #12, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ..................................................................................................... 99

Table 31: Test #13, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ................................................................................................... 100

Table 32: Test #14, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ................................................................................................... 1 01

Table 33: Test #15, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation ................................................................................................... 102

Table 34: Analysis of SAE .134 Distance Acceptability (25 - 26m) of Field Test #4 ...... 104
Table 35: Analysis of SAE J34 Distance Acceptability (25 - 26m) of Field Test #7 ...... 104
Table 36: Analysis of SAE 134 Distance Acceptability (25 - 26m) of Field Test #11....104
Table 37: Analysis of SAE J34 Distance Acceptability (25 - 26m) of Field Test #12....104
Table 38: Analysis of SAE J34 Distance Acceptability (25 - 26m) of Field Test #13....104
Table 39: Analysis of SAE J34 Distance Acceptability (25 - 26m) of Field Test #14....104

Table 40: Analysis of SAE J34 Distance Acceptability (25 - 26m) of Field Test #15 ....104

vi

LIST OF FIGURES

Figure l: A-Weighting Filter Effect Over the Range of Human Hearing .......................... 5
Figure 2: SAE J34 Boat Course for Pass-By Noise Measurement [copied at 150%,

with labels redrawn for clarity, from SAE J34, 2001] ................................................... 6
Figure 3: Planar Wave Propagation Model ........................................................................ 14
Figure 4: Spherical Wave Propagation Model ................................................................... 15
Figure 5: Boat Course for 1987 Lanpheer Pass-By Noise Measurements [reproduced

from Lanpheer, 1987] .................................................................................................. 17
Figure 6: Lanpheer's Sound Level Reduction as a Function of Distance (1987)

[reproduced from Lanpheer, 1987] .............................................................................. 18
Figure 7: Lanpheer's Attenuation Measured Over Water; Outboards & Sterndrives

(1993) [reproduced from Lanpheer, 1993] .................................................................. 19
Figure 8: Sound Level Compensation for Background Noise [reproduced from

Radcliffe, 2002] ........................................................................................................... 23
Figure 9: First Prototype of the Boat Noise Measurement Device .................................... 24
Figure 10: Pass-By Model of the First Noise Gun Prototype ............................................ 25
Figure 11: Second Prototype Functionality Block Diagram [copied from Vidanage,

2003] ............................................................................................................................ 26
Figure 12: Second Prototype of the Boat Noise Measurement Device ............................. 28
Figure 13: Pass-By Model of the Second Noise Gun Prototype with Minimum

Distance Shown ........................................................................................................... 29
Figure 14: Second Prototype Functionality Block Diagram .............................................. 30
Figure 15: Boat Course for Pass-By Noise Measurement ................................................. 33
Figure 16: Torch Lake Test Run [photograph by Betsy Dole] .......................................... 34

Figure 17: Test #12 Field Data, Measured SPLs (o) and Error-Compensated SPLs (I)
and Predicted SAE J 34 SPL (—) with Respect to the Measured SPLs Best-fit
Logarithmic Regression Line (—) ............................................................................... 36

vii

Figure 18: Test #12 Field Data, Measured SPLS (o) and Standard Deviation- and
Error Compensated-Corrected (X) SPLS with Respect to the Predicted SAE J34

SPL (—) ....................................................................................................................... 38
Figure 19: Cumulative Probability of the Data .................................................................. 40
Figure 20: Standard Normal Probability of the Data ......................................................... 40

 

Figure 21: Relative Amplitude Response Level of the A-Weighting ( ) and C-
Weighting (— —) Networks to a Steady-State Sinusoid [reproduced from ANSI

81.42-2001] .................................................................................................................. 48
Figure 22: Circuit Schematic of Noise Gun, rev. 3.1 ......................................................... 55
Figure 23: PC Board Layout (Top View) .......................................................................... 56
Figure 24: PC Board Layout (Bottom View) ..................................................................... 56
Figure 25: PC Board Layout (Component Placement View) ............................................ 57

Figure 26: Test #1 Field Data, Measured SPLS (o) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS and Predicted SAE J34 SPL (—) with Respect
to the Measured SPLS Best-fit Logarithmic Regression Line (—) .............................. 72

Figure 27: Test #2 Field Data, Measured SPLs (o) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS and Predicted SAE J34 SPL (—) with Respect
to the Measured SPLS Best-fit Logarithmic Regression Line (—) .............................. 73

Figure 28: Test #3 Field Data, Measured SPLS (o) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS and Predicted SAE J34 SPL (—) with Respect
to the Measured SPLS Best-fit Logarithmic Regression Line (—) .............................. 74

Figure 29: Test #4 Field Data, Measured SPLS (o) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS and Predicted SAE J34 SPL (—) with Respect
to the Measured SPLS Best-fit Logarithmic Regression Line (—) .............................. 75

Figure 30: Test #5 Field Data, Measured SPLS (o) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS and Predicted SAE J34 SPL (——) with Respect
to the Measured SPLS Best-fit Logarithmic Regression Line (—) .............................. 76

Figure 31: Test #6 Field Data, Measured SPLS (O) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS and Predicted SAE J34 SPL (—) with Respect
to the Measured SPLS Best-fit Logarithmic Regression Line (—) .............................. 77

Figure 32: Test #7 Field Data, Measured SPLS (O) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS and Predicted SAE J34 SPL (—) with Respect
to the Measured SPLS Best-fit Logarithmic Regression Line (—) .............................. 78

viii

Figure 33: Test #8 Field Data, Measured SPLS (o) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS and Predicted SAE 134 SPL (—) with Respect
to the Measured SPLS Best-fit Logarithmic Regression Line (—) .............................. 79

Figure 34: Test #9 Field Data, Measured SPLS (O) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS and Predicted SAE 134 SPL (—) with Respect
to the Measured SPLS Best-fit Logarithmic Regression Line (—) .............................. 80

Figure 35: Test #10 Field Data, Measured SPLS (o) and Standard Deviation- and
Error Compensated-Corrected (X) SPLS and Predicted SAE 134 SPL (—) with
Respect to the Measured SPLS Best-fit Logarithmic Regression Line (—) ................ 81

Figure 36: Test #11 Field Data, Measured SPLS (o) and Standard Deviation- and
Error Compensated-Corrected (X) SPLS and Predicted SAE 134 SPL (—) with
Respect to the Measured SPLS Best-fit Logarithmic Regression Line (—-) ................ 82

Figure 37: Test #12 Field Data, Measured SPLS (o) and Standard Deviation- and
Error Compensated-Corrected (X) SPLS and Predicted SAE 134 SPL (—) with
Respect to the Measured SPLS Best-fit Logarithmic Regression Line (—) ................ 83

Figure 38: Test #13 Field Data, Measured SPLS (o) and Standard Deviation- and
Error Compensated-Corrected (X) SPLS and Predicted SAE J34 SPL (—) with
Respect to the Measured SPLS Best-fit Logarithmic Regression Line (—) ................ 84

Figure 39: Test #14 Field Data, Measured SPLS (O) and Standard Deviation- and
Error Compensated-Corrected (X) SPLS and Predicted SAE 134 SPL (—) with
Respect to the Measured SPLS Best-fit Logarithmic Regression Line (—) ................ 85

Figure 40: Test #15 Field Data, Measured SPLS (o) and Standard Deviation- and
Error Compensated-Corrected (X) SPLS and Predicted SAE 134 SPL (—) with
Respect to the Measured SPLS Best-fit Logarithmic Regression Line (—) ................ 86

ix

KEY TO SYMBOLS AND ABBREVIATIONS

 

ASPLp/anar, doubling ......... Change in Planar Sound Pressure Level w/ Doubling Distance
ASPLspherical, doubling . Change in Spherical Sound Pressure Level w/ Doubling Distance
p .................................................... Value of Best-fit Logarithmic Regression Line (dBA)
p ........................................................................................................ Air Density (kg/m3)
a .......................................................................... Sound Level Standard Deviation (dBA)
r .............................................................................................................. Time Constant (s)
An ......................................................................................................... Normal Area (m2)
ANSI ....................................................................... American National Standards Institute
c ........................................................................................................ Speed of Sound (m/s)
' i ""'""’”/l
C ...................................... Compensatlon Constant, 201og10 1— 10 20 (dB)
ERMS ............................................................................... Exponential-Root-Mean-Square
I .......................................................... Sound Pressure Wave Acoustic Intensity (W/mz)
ICOMIA ........................................ International Council of Marine Industry Associations
ISO ............................................................. International Organization for Standardization
k ................................... Spherical Sound Propagation Constant, [J'wfsou'cfir] (N/m)
L p T ......... Exponential-Root-Mean-Square Sound Pressure Level (ANSI S l .4-1983) (Pa)
NASBLA .................................. National Association of State Boating Law Administrator
p ........................................................................... Time-Averaged Acoustic Pressure (Pa)
p(t) ............................................................. Acoustic Pressure as a Function of Time (Pa)

p0 ..................................................................... Reference Acoustic Pressure (2x10'5 Pa)

p b ............................................... Background Time-Averaged Sound Pressure Level (Pa)
pm ........................................ Total Measured Time-Averaged Sound Pressure Level (Pa)
p ref ................................................................... Reference Acoustic Pressure ( 2x10'5 Pa)
p s ........................................................ Source Time-Averaged Sound Pressure Level (Pa)
Pb ............................................ Background Time-Averaged Sound Pressure Level (dBA)
Pm ..................................... Total Measured Time-Averaged Sound Pressure Level (dBA)
PS .................................................... Source Time-Averaged Sound Pressure Level (dBA)
93mm? ........................................................... Sound Pressure Wave Acoustic Power (W)
r ........................................................................................................... Radial Distance (m)
SAE ................................................................................. Society of Automotive Engineers
SPL ......................................................................................... Sound Pressure Level (dBA)

xi

PROBLEM STATEMENT

Boat noise is a serious problem on Michigan lakes. The current boat noise
statutes are complicated to perform and are too easily disputed to have any effect in
controlling boat noise. This upsets some lakefront property owners who wish to enjoy
the naturally quiet atmosphere of the lakes. Something needs to be done to alleviate this
situation or else boat noise, which is unlawful, will continue to be a problem to Michigan

residents.

“We have a cabin on Higgins Lake where we go to enjoy peace and solitude in the
summer. However, in the past few years, many high powered watercraft brought to the
lake have destroyed our quiet with overload engines. ”

- Higgins Lake private citizen
Letter to the Governor

Boat noise disturbs and disrupts some lakefront property owners. The state of
Michigan has over 10,000 inland lakes, over 3,000 miles of shore on the Great Lakes and
roughly 1 million registered boats [www.michigan.gov/dnr/]. The current Michigan boat
noise standards in the Marine Safety Act (act 451 of 1994) require special test procedures
and do not take into account regular in-use boat operation [Marine Safety Act, 1994].
Law enforcement officials would like a simpler test procedure standard which regulates
boat noise in regular recreational use. A new method for enforcement of boat noise limits
is needed. There is a clear and existing problem with boat noise in the state of Michigan,
and the current solutions to that problem are ineffective.

Boat noise affects different aspects of local communities differently. Lakefront

property owners are disturbed and disrupted by boat noise. Law enforcement officials

would like a reasonable and enforceable standard based on the boat's noise level when in
normal operation. Boat owners would prefer a standard that wasn't an inconvenience.
The boating industry would like a better image in the community. Noise regulation
enforcement is a continuing problem for all elements in the lakefront community.
Michigan needs repeatable, reasonable and enforceable standards to regulate boat noise.
A repeatable and reasonable noise standard with method for enforcement will
help all parties adversely affected by boat noise. Lakefront property owners will no
longer be bothered by loud boats on their lake. Law enforcement will have an accurate
and repeatable standard to measure boat noise. The boating industry will gain a better
image from the public who operate quiet boats on inland lakes. A repeatable, reasonable

and enforceable boat noise standard will benefit everyone.

BOAT NOISE STANDARDS

Boat noise standards exist to set a method to quantify the magnitude of sound
emitted by a boat. The standards vary from static measurements of boats docked in idle
to measurements taken on boats in special operation. Each standard specifically lists the
terms and conditions under which the measurement must be taken to ensure a proper
scientific measurement. It is extremely difficult for law enforcement Officials to perform
the correct procedure and conditions as stated in the standards.

Boat noise standards are prepared by scientific organizations. The five standards
governing boat noise measurement were written by the Society of Automotive Engineers
(SAE), the International Council of Marine Industry Associations (ICOMIA) and the
International Organization for Standardization (ISO). The Michigan Marine Safety Act
(act 451 of 1994) uses two of the SAE standards to measure boat noise. The maximum
sound level a boat can produce is limited by the state of Michigan through these two
standards [Marine Safety Act, 1994].

The Society of Automotive Engineers (SAE) was the first organization to create a
standard to properly measure boat noise. "The [SAE] has more than 90,000 members -
engineers, business executives, educators, and students fi'om more than 97 countries -
who share information and exchange ideas for advancing the engineering of mobility
systems. SAE is [a] one-stop resource for standards development, events, and technical
information and expertise used in designing, building, maintaining, and Operating self-

propelled vehicles for use on land or sea, in air or space." [www.sae.org/about].

Later, the International Council of Marine Industry Associations (ICOMIA)
developed standards to measure boat noise. "[ICOMIA] was formed in 1965 to bring
together in one global organization all the national boating federations and other bodies
involved in the recreational marine industry, and to represent them at international level.
[ICOMIA] supports its members in every way possible and gives recommendations and
guidance on compliance with new international standards and regulations, publishes its
opinions and recommendations, and formulates drafi international standards and codes of
practice." [www.icomia.com/about-icomia/introduction.asp].

The most recent standards regarding boat noise were created by the International
Organization for Standardization (ISO). "ISO is a network of the national standards
institutes of 157 countries... [ISO] identifies what International Standards are required by
business, government and society, develops them in partnership with the sectors that will
put them to use, adopts them by transparent procedures based on national input and
delivers them to be implemented worldwide."
[http://www.iso.org/isolen/aboutiso/introduction/index.html].

The standards specify the exact characteristics required by the sound level meter
for a proper measurement. Each of the standards requires that the signal be A-weighting
filtered and given an explicit sampling time. Weighted filtering normalizes a given sound
pressure level measurement to the human response; human ears attenuate high and low
frequencies. The A-weighting filter mimics human ear response (Fig. l). The sampling
time defines the time over which sound level measurements are averaged. Slow and fast

sampling times correspond to 1 and 0.125 seconds, respectively [ANSI Sl.4-1983, 1983].

Further details regarding the A-weighting filter, along with the B-, C- and D-weighting

filters and sampling times are provided in Appendix A.

 

 

'70 I ' ' 11""! "*T‘Cl Milli—vfii' +1le

1 0 1 00 l 000 10000

Frequency (Hz)
Figure 1: A-Weighting Filter Effect Over the Range of Human Hearing

The SAE J34 Standard

The SAE 134 standard, Exterior Sound Level Measurement Procedure for
Pleasure Motorboats, was enacted in April, 1973. It was the first boat noise
measurement standard. The intent of the SAE 134 was "...to provide manufacturers of
marine equipment with a standard set of conditions and method of measurement of the
maximum sound level of boats and motors" through a 25 meter pass-by course [SAE J 34,
2001]. The method required setting a sound level meter on the shore of a body of water
or a dock projecting out from the shore into the body of water to measure the sound
pressure level of a passing boat. The boat follows a straight course marked by three
buoys, each 50 meters apart and 25 meters from the sound level meter, forming a line

perpendicular to the direction of measurement (Fig. 2).

""3:
I .1..- @

50m

.....l.

Figure 2: SAE 134 Boat Course for Pass-By Noise Measurement lcopiecLat 150%. with
@618 redrawn for clarity, from SAE 134. 2001]

 

The SAE 134 standard specifically states the microphone of the sound level meter
must to be 1.2 to 1.5 meters above the water and no less than 0.6 meters above the
platform, or shore, surface. The measured motorboat sound is the highest sound level

measured (dBA [App A], fast [App 8]) during the 25 meter pass-by.

The ICOMIA 45-98 and ISO 14509 Standards

The International Council of Marine Industry Associations (ICOMIA) 45-98 boat
noise standard, Determination of Reference Boat Parameters for Sound Emissions, was
created in October, 1999 as an international standard for measurement Of boat noise. The
ICOMIA 45-98 standard is based on the SAE 134 standard. The SAE 134 standard states
the time weighting characteristic of the sound level meter must be fast, whereas the
ICOMIA 45-98 standard states the time weighting characteristic of the sound level meter
must be slow. This change will eliminate any random sound pressure level impulsive

noise that may occur due to waves hitting the boat hull. It will also lower the maximum

sound pressure level value due to the increased sampling time. This change was made in
order to "...[Obtain] reproducible and comparable measurements of the pass by sound
pressure level emitted by powered recreational craft..." as stated in the standards Scope
[ICOMIA 45-98, 1991]. By eliminating random sound pressure level peaks, the results
will become more reproducible.

The International Organization for Standardization (ISO) 14509 international boat
noise standard, Small craft - Measurement of Airborne Sound Emitted by Powered
Recreational Craft, was created in November, 2000 by the European Union as a variation
of the ICOMIA 45-98 standard and a further variation of the SAE J 34 standard. It keeps
the same sound level meter slow time weighting characteristic as in the ICOMIA 45-98,
but changes its position. In the ICOMIA 45-98 and SAE 134 standards, the sound level
meter must be 1.2 meters to 1.5 meters above the surface of the water and at least 0.6
meters from the surface of the testing platform. The ISO 14509 standard states the sound
level meter must be 3.5 meters ($0.5 meters) above the surface of the water and 1.2
meters from the surface of the testing platform [ISO 14509, 2004]. This places the
microphone in a farther field of the sound source, where the sound reflection off the
surface of the water and the surface of the testing platform will be smaller, yielding a
more accurate measurement.

Pass-by measurement procedures are currently used nationally by 19 states and
the US. Coast Guard, where 86 dBA is the maximum acceptable sound level [Lanpheer,
2000]. The Michigan Marine Safety Act currently does not include the SAE 134

standard, or any pass-by measurement methods. Instead, it specifies the use of the SAE

11970 and 12005 standards, which are easier tO perform and do not require a detailed

course.

The SAE J] 970 and SAE J2005 Standards

The SAE 11970 and the SAE 12005 standards, Shoreline Sound Level
Measurement Procedure and Stationary Sound Level Measurement Procedure for
Pleasure Motorboats, enacted in December 1991, were the second and third boat noise
standards created for boat noise measurement. They were created to provide alternative
field procedures for measuring sound level emitted from pleasure motorboats. Their
development sought to avoid the requirement of a complicated pass-by course. The SAE
11970 and 12005 are the only two boat noise standards currently in law in the Michigan
Marine Safety Act.

The SAE 11970 boat noise standard, Shoreline Sound Level Measurement
Procedure, was enacted to be used for the measurement of sound emitted by pleasure
motorboats in operation on waterways where sound level restrictions apply. The setup
involves placing a sound level meter on the shore of a body of water, a dock projecting
out from the shore into the body of water, or a raft/boat moored to a dock or anchored so
that the sound level meter is not more than 6 meters from shore. The measurement is
taken after the boat accelerates fiIll throttle away from the measurement location for 30
seconds to emulate the Michigan Marine Safety Act's requirement for a 300 foot offshore
distance to boats operating at full throttle. The sound level meter must be placed 1.2

meters to 1.5 meters above the water and no less than 0.6 meters above the platform, or

shore, surface [SAE 11970, 1991]. Michigan Marine law sets a 75 dBA (slow) maximum
acceptable sound level from this standard measurement procedure.

The SAE 12005, Stationary Sound Level Measurement Procedure for Pleasure
Motorboats, boat noise standard was enacted for governmental agencies to enforce the
requirement for effective muffling means in pleasure motorboats. The idea is to measure
the sound level of a stationary motorboat in idle. The boat whose sound pressure level is
being measured must be either be moored or lashed to a stationary object. The sound
level meter needs to be placed 1.2 meters to 1.5 meters above the water and no closer
than 1 meter from the vertical projection of any part of the boat in the area adjacent to the
exhaust outlets [SAE 12005, 1991]. Michigan Marine law sets a 90 dBA (slow)
maximum acceptable sound level from this procedure.

Table 1 compares and contrasts the existing boat noise measurement standards by
their measurement type. The legal acceptable sound level limits are set by the local

governing body (state).

 

 

 

 

 

 

 

 

Table 1: Comgarison of Different Existing Standards

8 d d M T Date Time gag; hone iii? hone
tan ar easurement vpe —' -.—. or t om m t om

M MIME Platform Water
SAE 134 25m Pass-By Apr. 73 Fast 2 0.6m 1.2m - 1.5m
ICOMIA 45-98 25m Pass-By Oct. 99 Slow 2 0.6m 1.2m - 1.5m
ISO 14509 25m Pass-By Nov. 00 Slow 1.2m 3.5m :l: 0.5m
SAE11970 Lakeshore Emulation Dec. 91 Slow 2 0.6m 1.2m - 1.5m
SAE 12005 Lakeshore Emulation Dec. 91 Slow 2 1m 1.2m - 1.5m

 

 

 

 

 

 

 

 

SPECIAL CONDITIONS OF CURRENT BOAT NOISE STANDARDS

Special conditions are required for each of the boat noise measurement standard
procedures, such as the use of a dock, a large detailed course and short-distance
measurement devices. The standards are excellent scientific methods for boat noise
measurement; they provide repeatable measurements of the maximum boat noise level.
The goal of law enforcement, however, is to place limits on boat noise during operation.
None of the current standards regulate the measurement of maximum boat noise level
while the boat is in normal use. Law enforcement needs a standard to measure boat noise
while the boat is in normal use, as opposed to measuring boat noise under special
conditions.

Boat noise measurement standards measure the subject boat's ability to be loud;
they do not measure the noise level produced in normal use. They do not take into
account that a boat with the ability to be loud could be quietly operated, or that a quiet
boat could exceed the noise limits set in the Marine Safety Act. The situation is
comparable to a car capable of traveling over 100 miles per hour. It is not illegal to
purchase such a vehicle or drive it on local roads and highways. It is however, illegal to
exceed the maximum speed limit. It would be legal to travel 100 miles per hour on race
tracks and certain out-of—state highways, but only where designated. Cars capable of
traveling over 100 miles per hour are not prohibited. Loud boats should not be
prohibited. Boat operators should be able to be as loud as they like with respect to their
location. The noise level produced by use should be the basis for law enforcement

standards, not the boat's ability to be loud.

10

The standards use proper scientific measurement methods to measure the noise
level of a boat. This is conflicting with law enforcement measurements which would
provide a definite minimum value of the maximum sound level of the boat. This ensures
all errors are accounted for and the result is error-adjusted, rather than a scientific best-

estimate of the boat noise level.

11

SOUND PROPAGATION

Noise is produced by pressure waves which propagate through the air over
distance. There are two classic models of sound propagation, spherical and planar, which
model the least and most possible sound propagation over distance. Idealized planar
sound propagation models sound that does not spread in the direction of travel. Idealized
spherical sound propagation assumes pressure waves radiate and spread spherically from
a point source over an area increasing with distance. In different situations boat noise

may be best modeled with one, or a combination, of these classic propagation models.

The acoustic power of a pressure wave, 4’ remains constant at its source.

source ’
The magnitude of the acoustic intensity, I , (power per unit area) is given as a function of

acoustic power and normal area, A" .

(P
I : SOHI‘CG l
-—A ( )

n

The magnitude of the acoustic intensity is proportional to the square of the time-

averaged acoustic pressure, p , and inversely proportional to air density, p, and the

speed of sound, c [Pierce, 1981].
1 = £— (2)

Combining the relations (1) and (2), the local acoustic pressure is proportional to
the square root of the power of the source divided by the area over which the pressure

wave is traveling.

12

pc(P

source (3)

p- A

Sound pressure level (SPL) is measured in deciBels (dB) as a function Of the

measured pressure, p , and reference pressure, pref , 2x10‘5 Pascals.

 

SPL [dB] = zolog10 p (4)
pref

The reference pressure, pm f , is the smallest pressure wave a healthy human being

can hear at 1000 hertz as measured by the American National Standards Institute (ANSI)
[Pierce, 1981].

The change in sound pressure levels from two known distances, rl and r2 can be

rewritten as a function of the local acoustic pressures at those distances, p1 and p2 by
(4).

ASPL = 20 Iog,0[fl] (5)
PI

Planar Sound Propagation

Planar waves propagate unmitigated though the air as steady planes (Fig. 3).
Planar wave fronts travel in parallel planes; their energy does not dissipate with distance

because the area of the pressure wave remains constant with distance.

13

it I a
,3. r2.
V, ii p.
I: .

   

Figure 3: Planar Wave PropagaLtion Model

This model best fits sound propagating from a large vibrating surface, like the
side of a boat. Using (5) for planar waves, where the local acoustic pressure remains

constant over all distances (p1 = p2), the change in sound pressure level is zero with

distance.

P 2
ASPLp/anar, doubling = 2010g10[p—1] = 2010g10(l): 0 (6)

Spherical Sound Propagation

The spherical sound propagation model assumes a point sound source and sound
power spreads over an increasing area as it moves away from that source. The sound
pressure is spread over the increasing area of a spherical surface (Fig. 4) as a function of

the radial distance from the point source, r.

14

V

w

re4: _gu_Sp—p_g____ herical Wave Pro a ation Model

 

The acoustic power, T remains constant at the point source and the

source ’
acoustic intensity is given as a function of the half-spherical area of the pressure wave,

which is a function of radial distance, r.

source (7)

[spherical = 2

2m

It can be seen the acoustic intensity decreases with the inverse square Of the radial
distance. This is known as the spherical spreading law [Pierce, 1981]. Combining the
relations for acoustical intensity as a function of acoustic pressure and source power, (2)
and (7), the local acoustic pressure in spherical propagation is inversely proportional to

the distance from the source.

It
pspherical =7 (8)

The constant, k = pca,‘”“"%r . Substituting (8) into (5) and simplifying the

result yields the change in sound pressure level as a function of distance.

15

_ ’1
ASPLspherical - 2010g10[:2-] (9)

This shows the change in sound pressure level between two distances in the
spherical model is inversely proportional to the ratio of those two distances. The change
in sound pressure level, ASPL, with a doubling of distance is of particular interest in

noise measurements. Spherical propagation is a function of distance and for a doubling

of distance, (% =05), in pure spherical propagation, the sound pressure level
2

decreases by 6.02 deciBels.

ASPLspherim, 6,0“ng = 2010g10[-:;—] = 20 log10 (0.5) = —6.02dB (10)

The real nature of sound propagation from a boat is unknown; it is an unknown
combination of planar and spherical waves. Analyzing the planar and spherical models
gives the extremes of the range of the change in sound pressure with distance. Sound
cannot propagate more than 0 dB/doubling, as Shown by planar propagation, and cannot
propagate less than ~6.02 dB/doubling, as shown by spherical propagation. Real boats
have a combination of both propagation models and will always have a propagation value

between 0 and -6.02 deciBels with doubling of distance.

Richard Lanpheer's Sound Propagation Study

Experimental study of boat noise sound propagation was conducted by Richard
Lanpheer of Mercury Marine and the National Association of State Boating Law

Administrators (NASBLA) in January 1987. He used four sound level meters at four

16

known linear distances perpendicular to the direction of pass-by (Fig. 5) [Lanpheer,
1987]. Sound level meters at 50, 100 and 200 feet distances were used to analyze sound
propagation with doubling of distance. A 25 meter distance was used to analyze and

compare the measured sound pressure level to the SAE 134 standard procedure.

ii

 

 

200 ft

 

-EEJ

 

 

lOOfi g

25m

 

 

 

 

 

Figure 5: Boat Course for 1987 Lanpheer Pass-By Noise Measurements |reproduced
from Lanpheen 19871

17

Lanpheer tested 21 boat/motor combinations "...in an effort to determine the
effects of boat operational variables on sound level" [Lanpheer, 1987]. His results show
that doubling the distance between a boat and a microphone reduces the measured sound
level by an average of 5 dB/doubling (Fig. 6). All 21 boat/motor combination trials were
within 0.5 dB/doubling of the 5 dB/doubling average value with an exception of one, in
which only one of the three trial samples deviated by more than 0.5 dB/doubling
[Lanpheer, 1987]. His average 5 dB/doubling lies in the range of our two extremes
calculated from planar and spherical propagation, 0 and -6.02 dB/doubling, by (6) and

(10).

    

 

   

All
Twin Outboard

Stemdrive - Open Exhaust
Sterndrive - Muffled Exhaust
. Single Outboard
i Single Inboard

 

 

T l
40 50 60 70 80 90 100 200 300

Diatange (m
Figure 6: Lanpheer's Sound Level Reduction as a Function of Distance ( 1987)

l reproduced from Lanpheer, 1987|

 

 

 

18

Richard Lanpheer studied noise propagation in recreational boats again in
September 1992. One of the main purposes was to "...evaluate and compare existing and
proposed testing methods..." [Lanpheer, 1993]. He emulated the SAE J34 pass-by
standard and measured noise levels two distances, 25 meters, as stated, and 12.5 meters,
to observe the increase sound pressure level with doubling. His results indicated "...that
the average attenuation of sound pressure level between the two microphones was 4.9
deciBels" [Lanpheer, 1993]. This 4.9 deciBeI difference between the sound pressure
levels measured at 12.5 and 25 meters corresponds to an average of 4.9 dB/doubling (Fig.

7).

 

 

T
18 a
16 1
~ /
l4 4 //
12 /
lO /
- ,/
g 8 “I. /
6 —~ Case
4 1 7306‘
2 i
0 CT T’r l 7
10 20 3O 40 50 60 7O 80 90100
Mimi

Figure 7: Lanpheer's Attenuation Measured Over Water: Outboards & Sterndrives (1993)
l reproduced from Lanpheer, l993|

These pass-by test results compare well to the 5 dB/doubling result found in the
first tests. The tests themselves differ by definition. The first test is not comparable to
the SAE 134 standard. The second test is, yet they show the same result (within 0.1

dB/doubling). The two tests show 5 dB/doubling is an accurate assumption for

motorboat pass-by measurements. The results also indicate that, for various styles of

19

boats, in a pass-by measurement situation, this value stays quite constant. This
information and the sound propagation model can be used to calculate the sound pressure
level of a boat at any arbitrary distance given the sound pressure level at a known
distance.

In real world testing on a realistic lake, background sounds would interfere with
any possible measurements. Background sound level measurement needs to be

understood in order to strictly measure one specific sound source.

20

BACKGROUND SOUND LEVEL MEASUREMENT AND COMPENSATION

When a microphone measurement of a source sound level is made in the presence
of background noise, the total measured sound level is greater than the actual source
sound level. The oscillatory source and background sound levels combine to form a
single wave of greater amplitude. Each sound pressure level can be represented by its
exponential-root-mean-square (ERMS) value, which is derived and explained in detail in
Appendix B. The ERMS values of multiple sound sources can be added and subtracted,
regardless of phase, allowing for compensation analysis [ANSI Sl.4-l983, 1983].

The actual source sound level can be calculated when the background level is
known, for uncorrelated, broad-band sound levels. The total measured ERMS pressure

level, pm , is the sum of the source, p3 , and background, p b , ERMS pressure levels.

pm=ps+pb (11)

Acoustic pressure levels can be rewritten in terms of deciBeI units (dB) and vice
versa. This is done for convenience, as sound level meters tend to measure pressure

levels in units of deciBels rather than Pascals.

 

P[dB]=ZOlog10[ 1’ J (12)
pref

p = pref10(%0) (13)

The total measured sound, Pm in deciBels by (12), can be expressed as a function

of the sum of the source and background sounds, P5 and P , in deciBels by (11).

21

m M 1%)

= +1 (14)
The sound pressure level Of the source, PS, can be calculated by (12) and (14)

yielding the source sound pressure as a function of the total measured, and background

sound pressure levels.

11%) (a

—-10

PS [dB] = zoiog10 (15)

(15) can be factored and simplified to collect terms and compute the

compensation level in deciBels.
(Pb Tpml/
PS[dB]=Pm +2010gIO 1—10 20 (16)

This source sound pressure level equation, (16), can now be written to compute the

source sound pressure level and compensate for background noise.
PS [dB] = Pm [dB] + C [dB] (17)

The compensation can now be calculated as a function of the difference between the total

measured and background sound pressure levels.
—(Pm _Pb)/
C[dB]=2010g10 1—10 20 (18)

Since the total measured sound pressure level will always be greater than the

background source sound pressure level by itself, Pm —Pb will always be positive.

22

Mathematically this shows the compensation exponentially approaches zero as Pm — Pb

increases (Fig. 8).

 

om nsati n d
.L.
O

 

    

'20 " “*T' '— 1 l l ‘ ‘ l ' 1
0 5 10 15 20 25 30 35 40 45 50
‘ ‘ Noise Above “ ‘ J Noise. Ln - K—b (dB)

Figare 8: Sound Level Compensation for Background Noise |reproduced from Radcliffe,
2002|

As Pm 'Pb decreases, the sensitivity of the compensation calculation increases

exponentially. This can lead to a great deal of inaccuracy in compensation calculations.
The unacceptable sensitivity range (Fig. 8, shaded region) represents the range where the
sensitivity is greater than 1 dB/dB. The boat noise measurement device returns an error
readout for values in this range.

This analysis shows that a source’s sound level can be isolated experimentally for
a known background noise level. In a real world environment, background noises would
contribute error to the noise level measurement of a source. It has been demonstrated that
with a sole, constant background noise level measurement and a measured sound pressure
level at a known distance that a noise level for any source can be found accurately,

despite its distance.

23

FIRST BOAT NOISE MEASUREMENT DEVICE PROTOTYPE

In 2003, Sean Vidanage built a proof-of—concept boat noise measurement device
(Fig. 9) to experimentally study and measure boat noise sound propagation. He used a
programmable BASIC Stamp microcontroller along with external circuitry in conjunction
with a Contour XLR Laser Rangefinder to measure distance and a shotgun microphone to

measure sound pressure level.

 

Figure 9: First Prototype Of the Boat Noise Measurement Device

The purpose of this device was to demonstrate that a programmable
microcontroller, laser rangefinder and directional microphone could work together to
measure sound pressure levels and distances and perform calculations. The device
followed a boat, measured its distance and sound pressure level repeatedly, and
normalized the final sound level measurement to 25 meters. The operator could follow a

boat along any designated path (Fig. 10) and measure the corresponding distance, sound

24

level and calculate the normalized sound level at a 25 meter distance. The
microcontroller would calculate the amount of error associated with distance and
background noise automatically and correct the current sound pressure level to a law

enforcement value at 25 meters.

  

; “man-Lg

Figure 10: Pass-By Model of the First Noise Gun Protogcpe

The laser range finder would measure the changing distance of the boat during the
trial and the shotgun microphone would measure the corresponding sound pressure
levels. The device continuously corrected the measured sound levels with distance
assuming Lanpheer's best estimate of boat noise sound propagation of 5 dB/doubling (i1
dB/doubling). In a pass-by situation, the highest resulting sound pressure level is the
maximum noise level measured along the pass-by.

The first prototype proved that a laser rangefinder, shotgun microphone and
programmable microcontroller could work together. The BASIC Stamp microcontroller

could accept the readout of the laser rangefinder, it could accurately measure the shotgun

25

microphone signal and the resulting calculations were performed correctly. It was able to
function as planned and performed all the associated functions properly. A complete

functionality block diagram (Fig. 11) is shown to visually explain the steps.

Power
ON

7 Initialize

   
    
  

 

 

 

 

 

      

 

 

In ut Store
Distance

Time out PRINT

‘ Update ([3 . Corrected

Update dB Level ~ ‘13 Screen

Level ' . ’ .
PRINT: _ . Commie-133};
Upggted Distance ,CorrcctedzLE' ‘1;

Time out

 

 

Fi e 11: Second Proto eFunctionali Block Dia am co ied from Vidana e 2003

The first prototype was not designed to follow the SAE J34 pass-by standard.
The SAE J34 pass-by standard clearly states the sound level meter must be aimed
perpendicular to the direction of boat travel when measuring; the shotgun microphone
was aimed directly at the boat during the measurement. The first prototype was designed

to follow the boat along any course and continuously calculate the resulting 25 meter

26

corrected sound pressure level. It was designed as a proof-of-concept, an assembly of
necessary components into a working model. It accurately performed distance
independent noise measurements and calculations.

The microcontroller controlled all calculations and associated errors and
displayed them on an attached LCD monitor. The results show that the experimental
results match the mathematical model, with a reasonable error [Vidanage, 2003]. The
thesis strongly shows that, with some improvement, a boat noise measurement device

could be created for law enforcement purposes that follow the SAE J34 pass-by standard.

27

CURRENT BOAT NOISE MEASUREMENT DEVICE PROTOTYPE

Using the first prototype's circuit schematic and program code as a start, the

prototype design has been improved (Fig. 12).

 

Fi re 12: Second Proto e of the Boat Noise Measurement Device

 

LCD displays replaced the old LED displays, and a factory-produced silicon prototyping
board was created to hold the circuit components to help create space and limit hand-
soldering errors. An acoustic A-weighting filter, which complies with ANSI standards,
was added for acoustic filtering purposes. It complies with the A-weighting filter
requirement of all the existing standards.

The basic function of the second prototype differs greatly from the first prototype.
The second prototype method is modeled after the SAE J34 procedure. The SAE J34
standard states the microphone must be non-directional and point away from the dock

perpendicular to the course. A shotgun microphone was used to minimize background

28

noise, which requires the device operator to follow the boat along the course, rather than
place the unit stationary on the platform. The process involves following the boat with
the device along its course (Fig. 13). The device does not make any calculations until the

operator ends the measurement process.

 

 

F i e 13: Pass-B Model of the Second Noise Gun Proto c with Minimum Distance
Shown

 

In the second prototype method, distance and sound level are measured repeatedly
throughout the measurement trial. When the boat completes its pass-by, the
microcontroller returns the maximum sound level and the minimum distance along with
the corrected and background sound levels. This new procedure does not correspond to
the SAE J34 standard, but the two methods are similar and the results can be compared
for accuracy. A block diagram of the functionality of the second prototype is shown in

Figure 14.

29

 

Initialize hardware, software
and display screens

4:

Measure background sound,
'background sound level'

 

 

 

 

 

 

 

 

 

 

LWait for trigger I

 

 

 

Set 'maximum sound level' equal to
'background sound level;' measure
distance, 'measured distance;' set
'minimum distance' equal to
'measured distance'

 

 

 

 

 

'

 

 

r

Write 'minimum

distance' to small
LCD screen

 

 

 

 

I

Measure sound level, set as
'measured sound level'

 

 

 

 

    
       
 

ls 'measured sound
level' greater than

'maximum sound
level'?

No

Yes

1] Reset data I

 

 

 

Display results on

 

large LCD screen

 

 

 

 

Set 'maximum
sound level'
equal to
'measured
sound level'

 

 

 

 

 

 

 

 

Set 'minimum
distance' equal to
'measured distance'

 

Display ’measured
sound level' on small
LCD screen

 

 

 

 

 

   
 

Is 'measured
distance' less than
'minimum distance'?

  
   

Is trigger still
being pulled?

 

 

Measure distance,
I ‘ 0
measured distance

 

 

 

 

 

 

   

 

Correct 'maximum sound
level' for distance and
background sound level

 

 

Figure 14: Second Prototype Functionality Block Diagram

30

 

 

 

The device begins with initializing the software and hardware and powering the
system on. Then automatically, the device measures the background sound level of the
surroundings. This is the only time the background sound level is measured. The device
than waits for the user input (the trigger) and begins measuring only distance for an
approaching boat.

The second prototype model is programmed to initially set the background sound
level measurement to the 'maximum sound level measured,’ for use as a reference in later
loops. The initial distance is also recorded as the minimum distance, for comparison in
later loops. From there, constant distance and sound pressure levels are made. With each
measurement, the measured distance is compared to the minimum distance recorded, and
the lower of the two becomes the new minimum distance recorded, for the next loop.
The sound pressure level is measured and compared to the maximum sound pressure
level recorded and the larger is taken.

Once the trigger is released, the distance corrections are made to normalize the
result to 25 meters and the background noise corrections, following (18) are made to
isolate the desired source noise. The device then displays the minimum distance, the
maximum measured sound pressure level, the background noise level and the corrected
noise level value.

Given that this device is designed for law enforcement purposes, all errors must
go in favor of the offending boat operator. This implies all error measurements must be
maximized or minimized in calculations to give the offending boat all benefits of the
doubt. This separates a scientific measurement device from a law enforcement device. A

scientific measurement device would like to be as close a possible to the actual values

31

with the smallest and least amount of errors. A law enforcement device would like to be
as close as possible to actual values with all the errors skewed in favor of the offender.
This ensures that the resulting law enforcement measurement is the least possible value
that the offender could have been; and all the associated errors are in his/her favor.
Therefore any errors in measurement or correcting would only strengthen the
prosecution’s case. It is important to realize that a law enforcement measurement is
always lower than a scientific measurement, and that this device is a law enforcement
device.

The device uses a sound propagation worst case scenario to ensure a proper law
enforcement measurement. In Richard Lanpheer’s 1987 results (Fig. 6), he found an
average of 5 dB/doubling to be an accurate model of real boat sound propagation. In the
61 samples he conducted, only one had a difference from that average greater than i0.5
dB/doubling [Lanpheer, 1987]. Twice that difference, i1 dB/doubling, is used in the
second prototype to normalize the distance to 25 meters. Rather than use the 5
dB/doubling average value, the device skews the average within :tl dB/doubling. That’s
to say that if the boat was too close, the device would subtract the loudest possible value
it could have been, 6 dB/doubling. And if the boat were too far, the device would add the
quietest possible it could have been, 4 dB/doubling. This ensures the normalized distance
correction would be in favor of the offender, because any possible errors would only
make the boat louder.

The experimental testing took place on Higgins and Torch Lakes in northern
Michigan in June and September 2005 respectively. The test procedure was modeled

after the SAE J34 standard. Two additional courses were added to study propagation

32

with respect to doubling distance. A platform was erected such that a 50 meter by 100
meter area could be situated in front of it. Nine buoys marked three, three-buoy courses,
each different distances from the platform; one at 25 meters, one at half that, 12.5 meters,

and one at twice that, 50 meters (Fig. 15).

 

50m

\6
LII
O
3

#L

 

.-—7<'

a
9

 

 

Figgre 15: Boat Course for Pass—By Noise Measurement

The course is modeled afier the SAE J34 course, but the procedure was not
followed exactly. The platform wasn't assembled within the proper specification, the
microphone was not placed accordingly, and the boats didn't pass within 1 meter of the
far side of the buoys (Fig. 16). Though the course didn't follow the SAE J34 exactly, the

procedure was designed to be comparable to it.

33

 

Figgre l6: Torch Lake Test Run [photograph by Betsy Dole|

Assuming the acoustic power of the boat remains constant for all trials, there
should be roughly 5 dB/doubling in sound propagation, as there was in Lanpheer’s work.
The corrected values of each of the boats should be constant as well, with slightly lower
values as boats distances get smaller and larger than 25 meters. Since the distance error
is a function of how far the boat is from the 25 meter distance, a larger distance would
correspond to a larger error. Likewise, if the boat were very close to the 25 meter
distance there would be a very little error.

The purpose of this research is to create a law enforcement device and to compare
its results against Lanpheer's past sound propagation studies. The intent was to make
sure the noise measurement device under-predicts the sound level meter values every
time and to compare noise propagation with doubling distance to Richard Lanpheer's
results. Comparing the results will help determine the accuracy and validity of the noise

measurement device.

34

TESTING RESULTS

The microphone signal voltage was properly read from the shotgun microphone.
It was accurately amplified where the voltage produced by the maximum allowed sound
pressure level of the microphone corresponded to the threshold of the RMS-to-DC
conversion chip input. This was done using the microphones sensitivity information, and
checked experimentally with a function generator and oscilloscope repeatedly.

The amplified signal was filtered with a manufacturer-calibrated A-weighted
filter. A filtering chip applied the A-weighting filter to the shotgun microphone
measurement signal and showed no evidence of clipping, or distortion. The filter is
designed to comply with ANSI 81.42 standard which defines the proper design response
0f weighting networks for acoustical measurements [Applied Dynamic Measurements].

The sound pressure levels versus logarithmic distance are plotted for each test for
analysis, as described by (12). A typical example is shown in Figure 17 which shows
Test 12's data. The shaded area represents the range of distances acceptable in the SAE
J 34 standard. Each measured sound pressure level data point is shown (C). From these
POints, a best-fit logarithmic regression line (—) is obtained to determine the best
eStimate of the measured sound pressure level for any given distance. This lines slope is

Shown for comparison to Richard Lanpheer's data.

35

96 _-

    
 
 
   

 

 

 

if
< l
92 “ l ‘
> w I
ratedipted Y. ”L m ‘ A _ z_ W A
88 " J34 level I 1 I
m I I.
8 ——4
a 84 -* _
:3 I slope: -5.3dBA/doubling
‘ standard deviation: 0.6 dBA °
80 _.. T “i ‘ fiT —F— T r T
l0 12.5 20 25 30 40 50 60 70

Logarithmic Distance (m)
Figure 17: Test #12 Field Dag, Megsured SPLS (o) and Error-Compensated SPLS (I)

and Predicted SAE J 34 SPL {—1 with Respect to the Megured SPLS Best-fit
Logarithmic Regression Line {—1

The predicted SAE J34 sound level is found by the best-fit logarithmic regression
line (—). This value represents the predicted SAE J34 best scientific estimate of what the
sound pressure level of the boat would be at exactly 25 meters. This line will be
compared with each of the error-compensated calculated points (I), which are found by
(17).

The sound level propagation over distance compared well with Richard
Lanpheer's data. His experimentation led to overall boat sound propagation estimates of
-4.9 dB/doubling and -5 dB/doubling [Lanpheer, 1987; Lanpheer, 1993]. The results
indicated an average value of -4.86 dB/doubling, which is very close to each of his
experimental results.

The range of acceptable distances for the SAE J34 standard is represented by the
gray area in Figure 17. In order to properly perform the SAE J34 standard, the boat
needs to be within a 25 to 26 meter distance for each pass-by. This is extremely difficult

for an untrained operator. For the seven boats correctly tested, there were 26 total 25

36

meter pass-by measurements, of which only four (15.4%) would be acceptable by the
distance requirement of the SAE J34 standard procedure [App. G]. It is unlikely the
average boat operator could maneuver this course correctly by the SAE J34 standard to
make a proper measurement.

In order for the device to act as a proper law enforcement device, the
compensated values must be, at most, one standard deviation above the predicted SAE
J34 value. The standard deviation for this measurement procedure is calculated using the
same method as in the ISO 14509 standard. The ISO 14509 Standard Deviation of
Reproducibility Table (Table 2) takes into consideration all sources of uncertainty which
are considered to be independent of each measurement type. The International
Organization for Standards (ISO) defines the total standard uncertainty as the square root

of the sum of the squares of the individual standard deviations.

Table 2: Standard Deviation of Reproducibility [reproduced from ISO 14509, 2004]

 

 

 

 

 

 

 

 

 

 

Individual standard deviations of the
Individual sources of uncertainty maxrmum AS-wilf‘zlcd sound pressure
(dB)
Distance effects 0.25
Measuring equipment 1.0
Sound propagation conditions 1.5
Waves, currents and tides 1.5
Operator(s) effects 0.2
Test site variations 1.0
Operating conditions 0.5
Estimated total standard uncertainty 2.6

 

 

For the purposes of this measurement procedure, the ISO 14509 Standard
Deviation of Reproducibility Table is modified to remove the 'Sound propagation

conditions' uncertainty source because the device already corrects for this. With this

37

change, the total standard uncertainty of the boat noise measurement device measurement
procedure is calculated to be 2.1 dB.

Using the ISO 14509 Standard Deviation of Reproducibility method, the standard
deviation of uncertainty for this measurement procedure is 2.1dB. To compare the error-
compensated calculations to the SAE .134 best-estimate of the measured sound pressure
level, the standard deviation, 2.1dB, is subtracted from each calculation (Fig. 18, X). In
order for this device to function as a proper law enforcement tool, the standard deviation-
and distance and background noise error-corrected data points (X) must be less than the

best-estimate of the predicted SAE J 34 sound pressure level (-—).

 

 

 

96
fl 1
o l I
92 a 0 o o s ,
> --. O l
predicted ‘
8 88 a J34 level ‘9 o o
.. -- x x x l, x ,9
On X x I Xx
84 — l , a X
I" OO O
l
30 : l 1 l l . I 1
10 12.5 20 25 30 4o 50 60 7o

Logarithmic Distance (m)
Figure 18: Test #12 Field Data. Measured SPLs (0) 2m Standard Deviation- and Error

Compensated-Corrected (X) SPLS with Respect to the Predicted SAE J34 SPL (—)

Experimentally, the standard deviations of the seven acceptable experimental
results ranged from 0.5 dBA to 2.3 dBA [App. E] with a weighted average of 1.2 dBA,

by(19)

38

Z 0'.
— i j — 1 2dBA 19
aweighted—average — #Of total samples — ‘ ( )

# of trials [it of samples
1

 

The experimental weighted average standard deviation is considerably lower than the
value predicted by the ISO 14509 standard deviation of reproducibility method. This
shows the ISO 14509 value is a conservative value that will most likely over-predict the
standard deviation produced by a boat. In all the acceptable testing that was conducted
three out of 85 data points (3.5%) had standard deviation-corrections that were greater
than one ISO 14509 standard deviation (2.1 dB) larger than the predicted SAE J34 sound
pressure level [App. E, tests 11, 14]. All three of the values are less than 0.4 dB greater
than the predicted SAE J34 sound pressure level.

The standard deviation analysis is correct assuming the data fits Gaussian
distribution. Gaussian distribution implies "whenever a random experiment is replicated,
the random variable that equals the average (or total) result over the replicates tends to
have a normal distribution as the number of replicates becomes large" [Hubele, 2001].
An accurate way to tell if the data conforms to the Gaussian random variable normal
distribution is to compare the data to the cumulative probability function (Fig. 19). This
shows the percentage of the total trials covered in the entire range of normal random
variables. The plot shows that 50% of the data is less than, and the other 50% is greater
than, its corresponding best-fit logarithmic regression value. This makes sense assuming
half the measurements would be lower than expected and the other half would be greater

than expected.

39

 

 

l 1
u—3o u—26 u—o n n+0 “+26 u+3o
Normal Random Vgiable (dBA)

Figure 19: Cumulative Probability of the Data
The derivative of the cumulative probability function is the standard normal
probability function. This represents the typical 'bell curve' that Gaussian data conforms
to (Fig. 20). Data is lost in this representation due to column width definition; too thick a
column and standard deviation information is lost, to thin a column, and the less likely it

will appear to match the standard normal probability fimction.

 

 

8 i

6

a4 i

2 —
u—3o u—Zc u—c n n+6 p+26 u+3o

Mnnflfiandnmlariablfldfim
F iggre 20: Standard Normal Probabilig of the Data

40

Figure 19 shows excellent data conformity to the Gaussian distribution definition,
whereas it isn't as clear in Figure 20. Data conformity to Gaussian distribution shows the
data is reproducible with respect to a standard deviation. Although the weighted-average
standard deviation of the test data is 1.2 dB, the ISO 14509 standard deviation of

uncertainty for this measurement procedure is 2.1 dB.

41

CONCLUSIONS

The device operated correctly as designed. It was able to accurately measure the
distance to an approaching boat during pass by to find the closest point of approach.
Once the closest point was determined, the device accurately measured the largest sound
pressure level as the boat passed by. From the closest-point distance, the largest sound
pressure level measured, and the background sound pressure level, the microcontroller
was able to correct for distance to produce a best-estimate of the sound pressure level for
that boat at 25 meters. The gun displayed each of these values after each run for
evaluation purposes.

The laser rangefinder serial output signal was correctly read by the
microcontroller; this was proved by comparing concurrent displayed measurement values
from both the microcontroller, and the device. This process was done repeatedly to
ensure no mistakes had been made in programming.

Based on the data analysis, the following conclusions can be made:

0 Distance and sound level measurements can be made independently and correctly
interpreted by the BASIC Stamp microcontroller.

o The boat noise measurement device worked properly as designed.

o The data confirms Richard Lanpheer's sound propagation model assumptions
[Lanpheer, 1987; Lanpheer, 1993].

o It is possible to compensate for all errors (distance, background noise, standard

deviation) to yield conservative estimates of sound level at or below the SAE

J34, ICOMIA or ISO standard sound level.

42

o It is difficult for boats to follow the distance requirement of the SAE J34 standard;
25 to 26 meters during pass-by.

o The possible incorrect calibration of the device does not imply the device did not
work correctly as designed. An incorrect calibration would effect all sound
level measurements equally, meaning the measured sound levels would be off
by a constant value. This would not effect sound propagation analysis or

background noise compensation, by (18).

43

RECOMMENDATIONS FOR FUTURE WORK

0 Future models of the boat noise measurement device should replace the
directional shotgun microphone with an omni-directional microphone for field
calibration and SAE J34, ICOMIA or ISO standard conformity. This will also
allow for calibration without the use of an anechoic chamber.

0 A standard pass-by test site (or many standard pass-by test sites) should be
created. This will increase the ability to conduct future work. A permanent,
stable platform with dimensions outlined in one of the pass-by standards will
make emulating the current standards possible, and allow a safer working
environment for data collection.

0 The A-weighting filter should be moved into the circuit design rather than
implemented by a microchip. This will ensure proper function and ANSI
Sl.42-2001 compliance.

0 A low battery signal should be installed into the circuit model to alert the user
when the voltage levels are getting low.

0 The microcontroller program should be modified to subtract the standard
deviation of the measurement procedure as shown in the ISO 14509 standard.

0 C-weighting filtering should replace A-weighting filtering in noise measurement.
Loud boats large noise levels. A-weighting is used to filter small noise levels,

25 to 55 dB, whereas C-weighting is used to filter larger noise levels, 85 to

115 dB.

44

Appendix A:
Weighting Filter and Sampling Time Definitions

45

The weighting filter and sampling time characteristics of a sound level meter can
dramatically alter the results of a sound pressure level measurement. Weighting filters
add frequency-dependant aspects to the gain of the measurement. The sampling time of
the sound level meter defines the amount of time a signal is averaged, possibly
diminishing the quality of the result. Weighting filters and sampling times are specified

in all the boat noise standards discussed in this document.

Weighting Filters

Weighting filtering normalizes a given sound measurement to human response for
different deciBel ranges. The human ear attenuates high and low frequencies which must
be accounted for when analyzing human sound pressure level perception. Weighted
filtering normalizes the given sound pressure level to the appropriate sound pressure level
heard by humans. The weighted filters are designed to be the inverse of the Fletcher-
Munson equal-loudness contours; the plots of the necessary gain a frequency-dependant
signal requires to be of equal-loudness to a 1000 Hz reference tone [ISO 226:2003,
2003]. Since the tests were based on test subjects' opinions, Fletcher and Munson
averaged their results over many test subjects to obtain reasonable averages.

There are many existing acoustic weighting filters A-, B-, C-, and D- of which, A-
and C-weighing are the most popular. They happen to fall into convenient ranges where
humans perceive relatively quiet and loud sounds. For low-levels of sound measurement,
25 to 55 dB, the A-weighting filter is used to scientifically normalize a signal to human
sensitivity. For high-level sound measurement, 85 to 115 dB, the C-weighting filter is
normally used. The B-weighting filter exists for moderately high sound levels, between

the A and C ranges, which typically isn't important for acoustical measurement. The D-

46

weighting filter is used to measure aircraft sound levels and demolitions, at 115+ dB, a

range that would damage human hearing over time (Table 3).

  
  
 

  
  

25 to 55 dB
55 to 85 dB
85 to 115 dB
115+ dB

 
   

It is important to notice the shapes of the A- and C-weighting filters for low
frequencies. The filters seem to have the same general shape for frequencies larger than
1000 Hz, with a small difference (Fig. 21). For frequencies less than 300 Hz, there is a
large difference between the results. The difference between the A- and C-weighting
filters at 100 Hz is 20 dB, and the difference increases as the frequency decreases. If a
loud boat were to operate at a low frequency, the use of the A-weighting filter could

cause huge errors in sound level measurement.

47

nse Level dB

Res

 

'70 .:r 1

 

1111' j ll'.l 'l

10 100 1000 10000
Frequency (Hz)
Figure 21: Relative Amplitude Response Level of the A-Weighting ( 1 and C-
Weighting (— —) Networks to a Steady-State Sinusoid [reproduced from ANSI 81.42-
2001

 

 

Sampling Time

The sampling time defines the length of time over which sound level
measurements are averaged. Infinitesimally small measurements are not possible, so a
sound level wave may not be correctly measured in real time. Sampling times are the
specific time intervals over which an unknown sound pressure waves is measured and
averaged. Small sampling times yield large amounts of measurements, but may include
unwanted random peak noise. Large sampling times yield smaller amounts of data, and
tend to eliminate peak noise signals, but could eliminate wanted characteristics of the
pressure wave.

Slow and fast sampling times are formal terms corresponding to l and 0.125

seconds respectively [ANSI 81.4-1983]. These are the common sampling times

48

associated with boat noise measurement standards. The five standards discussed in this
document use and define sampling time by these definitions (Table 2).

The sampling time involved in an unknown sound wave measurement is very
important. For steady-levels with many random peaks, the slow sampling time would be
preferred. This will eliminate any random peak influence for a clear steady
measurement. For changing sound levels, a fast sampling time may be preferred. This
will yield a clearer depiction of the wave as the sound level changes, yet may include

random peak noise.

49

Appendix B:
The Exponential Time-Average Sound Pressure Level

50

The ANSI Sl.4-l983 standard provides the proper specification for sound level
meter measurements. As mentioned in Appendix A, sound level measurements have
sampling times associated with them because infinitesimally small measurements are not
possible. The standard defines the exponential-time-average sound pressure level as the
appropriate method for measuring time-varying sound waves in air. The sound pressure

level is given as Lpr [ANSI 814-1983], in deciBels, where 1 represents the time

constant (sampling time), as defined in Appendix A and p0 is the lowest acoustic

pressure level humans can possibly hear, 2x10“5 Pa (defined as p ref earlier).

I 2 (t—é)
L r(t)=1010g[i [ p—(ae [d5] (20)
p Koo 173

The mean of any single-variable continuous fimction, f (x), over a specific

interval, x = a to x = b , is given as the integral along that interval divided by the length

of the interval.
__ 1 b
flame," =f(x) =3— [f(§)d6 (21)
._ a a

The mean of an unknown pressure wave, p(t) , can be found by (22), where the interval

length is t.
__ 1 I
mm, = p(t) = ; [pew (22)
0

The mean-square of p(t) is derived from (23) and is measured as the integral of the

function squared.

51

— I
p(t)....,.-...,.... =p2<r>=§lp2<é>dé <23)
0

The root-mean-square of p(t), also called the quadratic mean, is a statistical

measure of the magnitude of a varying quantity. It is given as the square root of the

mean-square, from (23).

__ l
p(t)...,-m...-..,.... = We) = $1 fled: <24)
0

—:
The exponential-root-mean-square incorporates a first-order filter, e 4 , to the

root-mean-square, where the value inside the interval, p2(§) , decreases with respect to

the time constant, I .

 

1 t (5")
p(t)exp.-rool—mean-Square = J; ip2(§)e /Td§ (25)

The argument in the exponential filter is given as the difference between the
dummy integrating factor and the current time. This changes the bounds of the integral
from zero to t, to negative infrnity to t to encompass the limits of the filter. The filter
yields a value of zero for negative infinity and a value of one for t. Its exact value is a
function of the time constant, I , as defined in ANSI Sl.4-1983 and explained in

Appendix A.

The exponential-root-mean-square, in deciBels, is given as logarithmic function

of the ratio between the current measured acoustic pressure and the low threshold of

52

human hearing, pref. The logarithmic function is multiplied by 10 as a conversion from

the units of bels to deciBels. The coefficient is 10 rather than 20, as shown in (4),

because the argument in the integral is the squared ratio of acoustic pressure levels.

p(t) exp. — r00! — mean — square

I 2 (t—é)
[dB]=1010g l jiggle gag (26)
T 10
~00 ref

The ANSI Sl.4-1983 standard uses (20), which is equal to (26) with different

labeling, as the basis for a mathematical model to measure sound pressure levels.

53

Appendix C:
Circuit Schematic and PC Board Layout

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57

Appendix D:
Basic Stamp Program

58

'File: NoiseGun_CPM_1June2006.sz

'{SSTAMP 882} This Program is for the 882 microprocessor

'{SPBASIC 2.5) To be complied with PBASIC 2.5

'This file is based on "build4.b52" code by Sean Vidanage, modified by
' Clark Radcliffe for the NoiseGun PCB version 3 (6-18—06),

' "NoiseGun_CJR_12July2005.sz"

'THE 2x8 PARALLEL LCD (PART DMC50448N) CONNECTIONS SHOWN BELOW
' LCD pin Signal BSZ pin

' 1 0V Vss

' 2 5V Vdd

' 3 O-SV --- (Contrast control O-5V from pot.)

' 4 RS P1 (L = instruction, H = data)

' 5 R/W P2 (L = write data, H = read data)

' 6 E P3 (Enable signal)

' 7 D80 Vss (Data pin grounded, unused for 4 bit data)
' 8 D81 Vss (Data pin grounded, unused for 4 bit data)
' 9 D82 Vss (Data pin grounded, unused for 4 bit data)
' 10 D83 Vss (Data pin grounded, unused for 4 bit data)
' 11 DB4 P4 (Data bit, set by 882 byte B)

' 12 D85 PS (Data bit, set by 882 byte B)

' 13 DB6 P6 (Data bit, set by 882 byte B)

' 14 DB7 P7 (Data bit, set by 882 byte B)

'DEFINITIONS/INITIALIZATION, BASIC STAMP PINS

'2xl6 character serial LCD

LCD216 PIN O ' 'Serial I/O pin to 2x16 display
I

'2x8 character parallel LCD

E PIN 3 'LCD enable (1 = enabled)
Rw PIN 2 'Read/write

RS PIN 1 'Reg select (1 = char)
LcdDirs VAR DIRB 'Dirs for I/O redirection
LchusOut VAR OUTB 'I/O byte B is pins P4-P7
LchusIn VAR INB

I

'Rangefinder

Rangefinder CON 8

RangefinderL CON 9

'A/D converter

AD_CS PIN 13
AD_CLK PIN 14
AD_DO PIN 15

59

'DEFINITIONS/INITIALIZATION, CONSTANTS

'2x8 Character LCD display codes

Lchls CON $01 'Clear the LCD

LcdHome CON $02 'Move cursor home
LchrsrL CON $10 'Move cursor left
LchrsrR CON $14 'Move cursor right
LcdDispL CON $18 'Shift characters left
LcdDispR CON $1C 'Shift characters right
LcdDDRam CON $80 'Display data RAM control
LchGRam CON $40 'Character generator RAM
Lchinel CON $80 'DDRAM address of line 1
LchineZ CON $CO 'DDRAM address of line 2
LcdScrolle CON 250 'LCD scroll timing (ms)

'2x16 Character Serial LCD

baud4800 CON 16572
baud96OO CON 16468
LCD_8aud CON baud9600

'DEFINITIONS/INITIALIZATION, COMPUTATION
Z CON 500 'The maximum value of
' dB_Difference,
' 0 <= Ale6_Times < Z
' Make this an exact power of 2

L CON 125 'The number of intervals in the
' table

0 CON 4 'Z/L the width of catagories of
' AD_16_Times

M CON 16384 '65536/0 for the interpolation
' formula

Std_DIST CON 250 'Standard pass—by measurement

' distance (maxlO)

'DEFINITIONS/INITIALIZATION, VARIABLES (26 bytes = 13 Words available)

'Calculation/Results variables (retained always)

Ambient_d8 VAR Word 'Ambient SPL (d8x10)
Measured_d8 VAR Word 'Measured SPL (d8x10)
Corrected_d8 VAR Word 'Ambient corrected SPL (d8x10)
DIST VAR Word 'Distance to course (metersxlO)
d8_at_25m VAR Word 'Distance corrected SPL (d8x10)

'Temporary storage, used as defined below

WA VAR Word 'Temporary value
WB VAR Word 'Temporary value
WC VAR Word 'Temporary value
WD VAR Word 'Temporary value
WE VAR Word 'Temporary value
WP VAR Word 'Temporary value
WG VAR Word 'Temporary value

60

WH VAR Word

'2x8 character LCD variables

addr VAR WH

crsrPos VAR WG.BYTEO
Char VAR WG.BYTE1
idX VAR WF.BYTEO
scan VAR WF.BYTE1

'Lo calculation scratch variables
9

x VAR WA
Xf VAR X.BIT15
X2 VAR WB
x2f VAR x2.BIT15
lgx VAR WC
lng VAR lgx.BITO
lg VAR wo
lgO VAR lg.BYTEO
k VAR idx.NIBO
cc VAR idx.NIBl
bitk VAR WE.BITO

(only used

'Temporary value

'Address pointer
'Cursor position
'Character sent to LCD
'Loop counter

'Loop counter

in log calculation)

'Word for processing the number
'High bit of x, note alias

'For squaring the number

'High bit of x2, note alias
'Word will be the lg (base 2)

' of y, the mantissa
'Lowest bit of lgx,

' addressing

'To hold the log base 2
'For table lookup, array of
' bytes

'Loop and array index
'Characteristic of the log
'Temporary bit)

for bit

'DEFINITIONS/INITIALIZATION, EEPROM DATA

"Startupl", 0

"I O
O
O
O

Msgl DATA

Msg2 DATA " Ready!
Msg3 DATA "Ambz",

Msg4 DATA "Dstz",

MsgS DATA “d8A:",

Msg6 DATA "Amb-SP ", 0
Msg7 DATA " Error

H, O

61

 

'PROGRAM CODE

'Initialization Protocol. Wait for startup fluctuations to settle.
' Then build ambient sound level. Then proceed to operation mode.

LOW RangefinderL 'Turn on rangefinder I/O

GOSUB Startup_LCD28 'Initialize the 2x8 LCD display

GOSUB Startup_LCD2l6 'Write to 2x16 LCD to indicate
' machine is starting up

PAUSE 4000 'Pause 4 seconds for electrons
' to settle...

'Measure ambient sound pressure level SPL (dBA)
GOSUB AD_Conversion
Ambient_dB = Measured_dB
Corrected_dB = Ambient_dB
DEBUG CR, "Ambient Measured_dB: "

DEBUG DEC Ambient_dB/lO, ".", DECl Ambient_d8//1O
Ambient_dB = Measured_dB
SEROUT LCD216, LCD_Baud,[254,1] 'Clear 2x16 LCD screen
GOSUB Ambient_LCD28 'Display ambient on 2x8 LCD
' screen
WAIT_button: 'Wait for rangefinder button
' push
SERIN Rangefinder,baud4800,500,WAIT_button,[WAIT(",0"),DEC WA,DEC W8]
DIST = (WA*10 + W8)
WA = DIST 'Store current distance for

' output below

'At this point, we have the lst distance, so loop and display it.
Loop_Start:

DEBUG CR, "Current Distance=", DEC WA/10, ".", DEC WA//10

DEBUG " Min(distance)=", DEC DIST/10, ".", DEC DIST//1O
'Write distance to line 2 of 2x8 LCD screen
'Input: DIST (word)
'Position is 2x8 LCD line #2

char = Lchine2 'Get position on LCD

GOSUB LCD28_Command 'Set position on LCD

addr = Msg4

GOSUB LCD28_Put_String

char = Lchine2 + 4 'Now write 4 char value to LCD
' after "DST:" (value is in
' WA)

GOSUB LCD28_Write_Val

GetSound: 'Measure SPL
GOSUB AD_Conversion 'Get Measured_dB

'Find maxiumum(Measured_d8) and store in Corrected_dB

IF Measured_dB > Corrected_dB THEN Corrected_dB = Measured_dB
'Display Measured_dB

DEBUG CR,"Measured_d8:",DEC Measured_dB/IO, ".",DEC Measured_d8//10

DEBUG " Corrected_d8:",DEC Corrected_d8/10,".",DEC Corrected_dB//10

'Write Measured_dB to line 1 of 2x8 LCD screen
'Input: Measured_dB (word)
'Position is 2x8 LCD line #1

char = Lchinel 'Get position on LCD
GOSUB LCD28_Command 'Set position on LCD
addr = MsgS

GOSUB LCD28_Put_String
WA = Measured_dB

62

char = Lchinel + 4 'Now write 4 char value to LCD
' after "dBA:"
GOSUB LCD28_Write~Val
'Now get distance, use "timeout" to end loop...
SERIN Rangefinder,baud4800,500,Correct_d8,[WAIT(",0"),DEC WA,DEC W8]

WA = (WA*10 + WB)
IF WA < DIST THEN DIST = WA 'Store minimum (distance) in
I "DIST"
GOTO Loop_Start 'Start again
Correct_d8: 'End of loop, correct data
GOSUB Ambient_d8_Correction 'correct for Ambient level
GOSUB DIST_Correction 'Correct for distance
Display_Data_Summary:
GOSUB LCD216_Display2 'Print data Summary of 2x16 LCD
PAUSE 3000 'Wait a few seconds to make
' sure laser button is not
' pressed
Corrected_dB = Ambient_dB 'Reset constants
Measured_dB = 0
GOTO Wait_8utton 'Return to wait for trigger
' press to start measurement
' again
l======================================================================
'SUBROUTINE, 2x16 LCD display
Startup_LCD216:
SEROUT LCD216,baud9600,[254,1] 'Clear screen
PAUSE 20
SEROUT LCD216, baud9600, ["Initializing"]
PAUSE 20
RETURN

63

'SUBROUTINE, 2x16 LCD display

!

'Display Data Summary on 2x16LCD
'Dst:xx.xSPL:xx.x
'Amb:xx.x25m:xx.x
LCD216_Display2:

SEROUT LCD216, LCD_Baud,[254,1] 'Clear screen

PAUSE 20

SEROUT LCD216, LCD_Baud,["Dst:",DEC DIST/10,".",DEC DIST//10]
PAUSE 20

SEROUT LCD216, LCD_Baud,["SPL:",DEC Measured_d8/10,".",DEC
Measured_d8//10]

PAUSE 20

SEROUT LCD216, LCD_Baud,[SFE, $80+$40+(O)]

PAUSE 20

SEROUT LCD216, LCD_Baud,["Amb:",DEC Ambient_dB/lO,".",DEC
Ambient_dB//10]

PAUSE 20

SEROUT LCD216, LCD_Baud,["Cor:",DEC Corrected_dB/IO,".",DEC
Corrected_d8//10]

PAUSE 2O
RETURN

'SUBROUTINE, 2x8 LCD screen

I

'Initializes 2x8 LCD screen, writes stored (in DATA statement) zero-
' terminated string to LCD

' -- position LCD cursor

’ -- point to zero—terminated string (first location in 'addr')
Startup_LCD28:

DIRL = %11111110 'Setup pins for LCD

LchusOut = %0011 '8-bit mode

PULSOUT E, 3 : PAUSE 5 '3 => 3*2 usec = 6 usec & 5 = 5
' msec

PULSOUT E, 3 : PAUSE O
PULSOUT E, 3 : PAUSE O

LchusOut = %0010 '4-bit mode

PULSOUT E, 3

char = %00101000 '2-line mode

GOSUB LCD28_Command

char = %00001100 'On, no cursor, no blink
GOSUB LCD28_Command

char = %00000110 'Increase cursor, no

' displacement shift
GOSUB LCD28_Command
'Write "Startup" message on 2x8 LCD screen
char=LCDcls
GOSUB LCD28_Command
char=Lchine2
GOSUB LCD28_Command

addr=msg1
GOSUB LCD28_Put_String
RETURN

64

'SUBROUTINE, 2x8 LCD screen

I

'Write ambient level on 2x8 LCD screen
'Input: Ambient_dB (word)

'Position is 2x8 LCD line #1

Ambient_LCD28: 'Write "Amb: " to first line

' on 2x8 LCD screen

char = Lchinel 'Get position on LCD

GOSUB LCD28_Command 'Set position on LCD

addr = Msg3

GOSUB LCD28_Put_String

WA = Ambient_dB 'Now write 4 char value to LCD
' after "Amb:"

char = Lchinel + 4
GOSUB LCD28_Write_Val

char = Lchine2 'Now write " Ready!" on lst
' line
GOSUB LCD28_Command
addr = Msg2 'Point to message
GOSUB LCD28_Put_String 'Write it
RETURN

'SUBROUTINE, 2x8 LCD screen

I

'Write a zero-terminated string stored in EPROM DATA to 2x8 LCD at
' current cursor position

' Input: "addr" address of string

LCD28_Put_String:

DO
READ addr, char
IF (char = 0) THEN EXIT
GOSUB LCD28_Write_Char
addr = addr + 1
LOOP
RETURN

'SUBROUTINE, 2x8 LCD screen

I

'Send command to LCD

' -- put command byte in 'char'

LCD28_Command: 'Write command to LCD
LOW RS
GOTO LCD28_Write_Char

65

_—-—_——_——————____———_———_——_———_———_——_—__—————.—.—-—————~_——————————___
————-——————_-_-—-———-——_——_-—————————.—_——-——————_———————_————_--———————

'SUBROUTINE, 2x8 LCD screen

I

'Write character to current cursor position then increment current
' cursor position

' -- but byte to write in 'char'

LCD28_Write_Char: 'Write character to LCD
LchusOut = char.HIGHNIB 'Output high nibble
PULSOUT E, 3 'Strobe the enable line
LchusOut = char.LOWNIB 'Output low nibble
PULSOUT E, 3
HIGH RS 'Return to character mode

RETURN

'SUBROUTINE, 2x8 LCD screen
I
'Write a single character "0-9" to current cursor position
'ASCII "O" = 48
LCD28_Write_Digit:
char = char + 48
GOSUB LCD28_Write_Char
RETURN

'SUBROUTINE, 2x8 LCD screen

I

'Write a 4 digit value "WA" as string to EPROM starting at "char"
' char = byte address of M58 digit in 2x8 LCD screen memory

' Note: the ACSII value of the charcter "0" is 48

' 4 digit value has decimal point between 10's and 1's digit
LCD28_Write_Val:

GOSUB LCD28_Command 'Send address of lst character
char = WA/lOOO 'Get 1000's digit
IF char = 0 THEN 'Scaled value is less than 999,

' so print as XX.X ignore
' 1000's digit

W8 = WA//1000 'Get remander

char = WB/IOO 'Get value of 100's digit

GOSUB LCD28_Write_Digit 'Write it to 2x8 LCD

WB = WB//100 'Get remainder

char = WB/IO 'Get value of 10's digit

GOSUB LCD28_Write_Digit 'Write it to 2X8 LCD

char = "." 'Decimal point

GOSUB LCD28_Write_Char 'Write it to 2x8 LCD

char = W8//10 'Get value of 1's digit

GOSUB LCD28_Write_Digit 'Write it to 2x8 LCD

ELSE 'Scaled value is 1000 or more,

' print as XXX. (round 10's
' digit)

GOSUB LCD28_Write_Digit 'Write 1000's digit to 2x8 LCD

W8 = WA//1000 'Get remander

char = WB/IOO 'Get value of 100's digit

66

GOSUB LCD28_Write_Digit 'Write it to 2x8 LCD

W8 = W8//1OO 'Get remainder
char = WB/lo 'Get value of 10's digit
WB = W8//10 'Get value of 1's digit
W8 = (WB + 5)/10 'Round it off
char= char + WB 'Add round-off to 10’s digit
GOSUB LCD28_Write_Digit 'Write it to 2x8 LCD
char = "." 'Decimal point
GOSUB LCD28_Write_Char 'Write it to 2x8 LCD
ENDIF

RETURN

'SUBROUTINE, A/D Converter with filter code

'Returns 10 bit value in "A"
AD_Conversion:

WA = 0 'Reset accumulator
FOR idx = 1 TO 4
GOSUB AD_GetData 'Get 8 bit data value into "8"
' (0-255)
WA = WA + W8 'Accumulate in "A" to yield 12
' bit value (0-1020)
NEXT
Measured_dB = 1020 - WA 'A/D decreases with increasing

' SPL, invert scale here
DEBUG CLS, "Measured_d8=", DEC Measured_dB
RETURN

'SUBROUTINE, A/D Converter with filter code

AD_GetData:
LOW AD_CS 'Select A/D chip
LOW AD_CLK 'Initialize clock pin
PULSOUT AD_CLK,10 'Pulse clock to start A/D

' conversion
SHIFTIN AD_DO,AD_CLK,MSBPOST,[WB\8] 'Get A/D data into "W8" with
' syncronous serial protocol
HIGH AD_CS 'Deselect A/D chip
RETURN

67

'SUBROUTINE, A/D Converter with filter code

'The ambient noise Db correction subroutine finds the appropriate

' ambient noise correction based on the difference between the

' measurement SPL (dBA) and the ambient background SPL. This

' correction is then used to reduce the measured SPL (dB) and compute a
' corrected SPL (dB). The correction is approximate BUT always equals
' the exact correction for the minimum difference in each case. The

' values can be computed with

' correction = -20*log10( 1—10“(difference/20))

' where difference = ambient - measured (d8)
Ambient_d8_Correction:

Measured_dB = Corrected_dB 'Store max SPL
SELECT (Measured_dB - Ambient_dB) 'Correct max SPL for ambient
CASE < 59 'Measured < ambient + 6d8
Corrected_dB = 0 'Error
char = Lchinel 'Print "Amb:" on 2x8 LCD line 1
GOSUB LCD28_Command 'Set position on LCD

addr = Msg6

GOSUB LCD28_Put_String

char = Lchine2 'Print "Error" on 2x8 LCD line2

GOSUB LCD28_Command 'Set position on LCD

addr = Msg7

GOSUB LCD28_Put_String

Measured_dB = Corrected_dB'Retrieve max(Measured_d8)

Corrected_dB = 0 'Zero Corrected_dB since there
' is an ambient error

DEBUG CR, "Ambient Level Error"

CASE 60 TO 79 'Measured 6-8 d8 above ambient
Corrected_dB = Corrected_dB - 60 'Subtract 6.0 dB
CASE 80 TO 99 'Measured 8—9.9 d8 above
' ambient
Corrected_dB = Corrected_dB - 44 'Subtract 4.4 dB
CASE 100 TO 120 ‘Measured 10-12 dB above
' ambient
Corrected_dB = Corrected_dB - 33 'Subtract 3.3 dB
CASE 121 TO 150 'Measured 12.1-15.0 d8 above
' ambient
Corrected_dB = Corrected_dB - 25 'Subtract 2.5 dB
CASE 151 TO 210 'Measured 15.1-21.0 d8 above
' ambient
Corrected_dB = Corrected_dB - 17 'Subtract 1.7 dB
CASE 211 TO 250 'Measured 21.1-25.0 d8 above
' ambient
Corrected_dB = Corrected_dB - 8 'Subtract 0.8 dB
CASE 251 TO 293 'Measured 25.1—29.3 d8 above
' ambient
CorrectedmdB = CorrectedfidB - 5 'Subtract 0.5 dB
CASE 294 TO 387 'Measured 29.4-38.7 dB above
' ambient
Corrected_dB = Corrected_dB - 3 'Subtract 0.3 dB
CASE 388 TO 449 'Measured 33.8-44.9 dB above
' ambient
Corrected_dB = Corrected_dB - 1 'Subtract 0.1 dB

68

CASE 450 TO 1023 'Measured more than 45.0 dB
' above ambient
Corrected_dB = Corrected_dB ' No Correction
ENDSELECT
RETURN

———————-————————_—-——-——————--————————-——-—————_—-———-———-————————————

'SUBROUTINE, A/D Converter with filter code

'Enter with DIST defined as measured distance to course (meters x 10
' = dm) d8_at_obs defined as measured dB at observer position
' d8_at_obs is in units of 10*d8 = Bels (80.1 dB => 801 Bel)
'Correction: Add 4 dB/doubling for distances more than 250 dm subtract
' 6 dB/doubling for distances less than 250 dm
DIST_Correction:
GOSUB Log_DIST '1g = log2(DIST)
' DEBUG CR, "lg =", DEC lg 'note: Log2(250) = 7.96 => 796
' here (Log2*100)
SELECT (DIST)

CASE < 250 'Measurement at less than 25 m
WA = (796 - 1g)*6/10 'Correction is negative 6
' dB/doubling
Corrected_dB = Corrected_dB - WA '6 d8 per doubling
' subtracted
CASE = 250
Corrected_dB = Corrected_dB
CASE > 250 'Correction is positive for

' distance > 25m
(lg - 796)*4/10 + Corrected_dB '4 d8 per
' doubling added

Corrected_dB

ENDSELECT
RETURN

69

'SUBROUTINE, A/D Converter with filter code

'Log base 2 of distance calculation. Measurement DIST is in dm

' (decimeters). Log calculation is for integers. Algorithm from Sean
' Vidanage's code.
'note: log2(250) = 7.96 => 796 here (Log2*100)
' d8_at_obs is in units of 10*d8 = Bels (80.1 dB => 801 Bel)
Log_DIST:
cc = NCD (DIST) - 1 'Find the characteristic
x = (DIST) << (15 - cc) 'Adjust for a denominator of
' 32768 optionally, show the
' decompostion
lgx = O 'Initialize accumulator
FOR k = 14 TO 0 '15 steps of precision
x2 = x**x 'High byte of x squared
1gx0(k) = x2f 'High bit of x squared is this
' bit of log.
bitk = ~x2f 'Complement of that bit
x = x2 << bitk + (bitk&xf) 'Adjust x
NEXT 'Repeat, combine it into one 16
' bit word (but lose one
digit!):
lg = cc*100 + (lgx**2000/10) 'log2(DIST) base 2
RETURN

70

Appendix E:
Field Data

71

Test Number: 1

Hull IdentificLion: MC4728SJ
Boat Operator: (not recorded)
Dite: 7-19-2005

L_oc_zytio_n: Higgins Lake, MI

Comments: This data set is NOT used in the analysis due to the different device
calibration between this data set and the Torch Lake data sets.

Table 4: Test #1 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Trial # M Minimum Distance Maximum SPL Measured Background Corrected
— §_ic_le_ Measured (m) Measured (dBA) Norse SPL (dBA) SPL (dBA]
1 Port 52.6 78.1 52.7 81.8
2 Star. 53.4 75.8 52.7 79.4
3 Port 51.4 80.6 52.7 84.2
4 Star. 53.7 78.6 52.7 82.5
5 Port 26.1 82.9 52.7 82.8
6 Star. 27.0 80.5 52.7 80.7
7 Port 27.5 83.0 52.7 83.2
8 Star. 27.1 81.4 52.7 81.3
9 Port 26.5 67.6 52.7 65.4
10 Star. 27.5 81.1 52.7 81.1
1 1 Port 16.4 80.9 52.7 76.8
12 Star. 28.4 66.0 52.7 64.2
13 Port 15.4 83.1 52.7 78.6
14 Star. 15.1 81.6 52.7 76.8
15 Port 15.4 71.8 52.7 65.9
16 Star. 15.2 81.2 52.7 76.4
17 Port 14.9 70.7 52.7 65.7
18 Star. 14.8 70.7 52.7 65.7

85 :3
60 It); x
0 (ix 0
m 80 1% ‘Q—b
> X I . . o
__) 75 T y, x slope. 0.6 dBA/doubling
8 o (1“ standard devratron: 5.6 dBA
3 70 ° '7
l o
n 65 '4 °
xx 1 TX
x
60 ? T i T T T T T
10 12.5 20 25 30 40 50 60 70

Logarithmic Distance (m)
Figure 26: Test #1 Field Data. Mea_sured SPLS (O) and Standard Deviyajion- and Error

Compensated-Corrected (X) SPL_s_§nd Predicted SAE J 34 SPL (—)with Respect to thp
Measured SPLS Best-fit Logarithmic Reggession Line (-—)

 

72

Test Number: 2

Hull Identification: MC8487SV
Boat Operator: (not recorded)
9% 7-19-2005

Location: Higgins Lake, MI

Comments: This data set is NOT used in the analysis due to the different device
calibration between this data set and the Torch Lake data sets.

Table 5: Test #2 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

   

 

  

Trial # M Minimum Distance Maximum SPL Measured Background Corrected
_ Side Measured (m) Measured (dBA) Noise SPL (dBA) SPL (dBA)
1 Port 30.6 67.5 51.3 66.9
2 Star 27.6 66.6 51.3 65.4
3 Port 29.0 65.9 51.3 64.2
4 Star 20.3 68.2 51.3 64.7
5 Port 15.7 70.2 51.3 64.5
6 Star. 15.5 70.2 51.3 64.4
7 Port 14.6 69.9 51.3 63.6
8 Star. 15.1 69.9 51.3 63.9
9 Port 50.9 61.8 51.3 62.6
10 Star. 51.8 62.0 51.3 62.9
11 Port 51.3 60.4 51.3 60.1
12 Star. 52.1 61.9 51.3 62.8
13 Port 51.7 60.1 51.3 59.9
14 Star. 51.5 62.2 51.3 63.0

72
<
o
> slope: -4.9 dBA/doubling
h 64 standard deviation: 0.9 dBA
§ 60 —
56

 

 

10 12.5 20 25 30 40 50 60 70

Logarithmic Distance (in)
Figure 27: Test #2 Field Data, Measured SILS (Qand Standard Deviation- and Error

Compensated-Corrected (X) SPLsfld Predicted SAE J 34 SPL (—) with Respect to the
Msured SPLJs Best-fit Logarithmic Reggession Line (—)

 

 

73

Test Number: 3

Hull Identification: MC4387PE
Boat Operator: (not recorded)
D_at_§: 7-19-2005

_I_._gg_a_t_io_n: Higgins Lake, MI

Comments: This data set is NOT used in the analysis due to the different device

calibration between this data set and the Torch Lake data sets.

12% 6: Test #3 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

    
 

 

 

Trial # oat Minimum Distance Maximum SPL Measured Backggound Corrected
— Side Measured (m) Measured (dBA) Noise SPL (dBA) SPL (dBA)
1 Port 50.9 58.8 51.3 56.9
2 Star. 50.3 62.5 51.3 63.2
3 Port 24.8 66.5 51.3 64.8
4 Star. 26.9 65.7 51.3 63.6
5 Port 12.9 71.2 51.3 63.8
6 Star. 12.1 71.2 51.3 63.2
7 Port 50.3 60.7 51.3 60.3
8 Star. 50.1 61.9 51.3 62.6
9 Port 25.2 67.1 51.3 65.4
10 Star. 26.8 65.5 51.3 63.4
11 Port 12.6 71.2 51.3 63.6
12 Star. 14.2 69.8 51.3 63.2

72
68
g If“ slope: -5.0 dBA/doubling
64 ’ ' standard deviation: 0.9 dBA
x ’9‘ x . X 8
"’ 60 I.)
T} ,9
56 ~ '2
[ i. X
L.
52 T T T T T T
10 12.5 20 25 30 4O 50 60 70

ngarithmic Distanga (1p)

Figpre 28: Test #3 Field Dat_a, Measured SPLS (o) and Standard Deviation- and Error
Compensated-Corrected (X) SPL_s_a_nd Predicted SAE J 34 SPL (—) with Reppect to the

Measured SPLs Best-fit Logarithmic Regression Line (—)

 

74

Test Number: 4

Hull Identification: MC3706PB

Boat Operator: Tim Tilley

_D_a_t§: 9-10-2005

L_oca_tipp_: Torch Lake, MI

Comments: Antrim County Sheriff's Department Boat; Twin 150HP Evinrude 2 stroke

Table 7: Test #4 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  
  

 

  

 

 

Trial # M Minimum Distance Maximum SPL Measured Background Corrected
— Side Measured (in) Measured (dBA) N0ise SPL (dBA) SPL (dBA)
1 Star 17.6 80.4 32.6 77.4
2 Port 31.4 77.5 32.6 78.7
3 Port 14.7 82.9 32.6 78.3
4 Star. 56.5 71.6 32.6 76.2
5 Port 25.7 78.0 32.6 78.1
6 Star. 12.9 81.2 32.6 75.5
7 Star. 52.7 72.1 49.4 75.6
8 Port 52.6 71.1 32.6 75.0
9 Port 13.4 81.9 49.4 76.2
10 Star. 26.5 76.0 49.4 75.8
11 Port 51.1 70.3 49.4 72.7
12 Star. 26.7 75.5 49.4 75.4

84
m
“>3 . '_'.-:
L_g _ , , - ~~ _o___+- l . ___-
o 76 _ x slope: -5.4 dBA/doubling
a x ,ng standard deViation: 1.1 dBA
x
:i: X 1' >5:
c, 72 — (
m — I
63 T i ‘ T T , 1
10 12.5 20 25 30 40 50 60 70

Logarithmic Distance (m)
F igi_1re 29: Test #4 Field Data, Mefled SPLS (o) and Standard Deviation- and Error

Compensated-Corrected (X) SPLaand Predicted SAE J34 SPL (—-) with Respect to the
Measured SPLs Best-fit Logarithmic Reggession Line (—)

75

Test Number: 5

Hull Identification: MC3457SN
Boat Operator: Bill Johnson
Dat_e: 9-10-2005

LoLtion: Torch Lake, MI

Comments: Yellow Catamaran dual hulls; 900HP, 4 stroke, V8 supercharge Teague,
Gatling mufflers. This data set is NOT used because there weren't enough trials.

Boat Minimum Distance Maximum SPL Measured Background Corrected

Trial #

Port 40.4 101 32.7 103
Port 46.5 98.0 32.7 101
Star. 65.3 97.4 32.7 102
Port 74.7 93.5 32.7 99.8
Star. 28.3 101 32.7 101
Port 44.7 92.6 32.7 95.9

 

 

     
 

 

 

100 .2 x
3’ x
3 98 .- o o x
slope: -4.5 dBA/doubling
96 l standard deviation: 2.8 dBA
r T“,
G
94 x
m ,,, C
L r o
92 - T “' T T T T T
10 12.5 20 25 30 40 50 60 70

L ari ic Distan e

Figge 30: Test #5 Field Data, MeasLured SPLS (o) and Standard Deviation- and Error

Compensated-Corrected (X) SPLS and Predicted SAE J 34 SPL (-—) with Respect to the
Measured SPLs Best-fit Logarithmic Regression Line (—)

 

76

Test Number: 6

Hull Identification: MC3529PB

Boat Operator: Heather Wilson, sheriff's dept.
M: 9-10-2005

m: Torch Lake, MI

Comments: Antrim County Sheriffs Department Boat; 200 Mercury, 2 stroke, 21.5', DC
Aquasport. This data set is NOT used because of possible wind effects.

Trial #

Level

ound

l
2
3
4
5
6
7
8
9

 

 

80 t Minimum Distance Maximum SPL Measured Background Corrected
Port 14.6 72.8 44.2 67.7
Port 14.8 81.6 55.6 76.6
Star. 16.6 79.7 55.6 75.4
Port 15.5 81.6 55.6 77.0
Port 31.5 75.2 55.6 74.8
Star. 29.9 74.9 55.6 74.2
Star. 55.5 69.5 55.6 71.6
Port 53.1 67.2 55.6 68.2
Star. 53.0 69.4 55.6 71.2

 

 

    
 

 

l

l

l
1.:
l?

I

l

l

1

 

 

_, X x x . slope: -5.6 dBA/doubling
o x LT x standard deviation: 2.5 dBA
,1 x
.1 o
x ~: x
L1
1 l l l I I I
10 12.5 20 25 30 40 50 60 70

Logarithmic Distance (m)

Figure 31: Test #6 Field Dfl Mgsured SPLS (o) and Standard Deviation-41nd Error
Compensated-Corrected (X) SPLS and Predicted SAE J 34 SPL (—) with Respect to the

 

Measured SPLs Best-fit Logarithmic Reggession Line (—)

77

Test Number: 7

Hull Identificagicm: MC3220RP

Boat Operator: Bill Johnson

Die; 9-10-2005

Lamp: Torch Lake, MI

Comments: 2 HB500 Birkhauser formula 350, 35.5', FASTech

Table 10: Test #7 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  
  

 

 

 

. . . *

Trial # Boat Minimum Distance MaXimum SPL Measured Background Corrected
—" Side Measured (in) Measured (dBA) Noise SPL (dBA) SPL (dBA)
1 Port 13.4 88.0 42.1 82.6
2 Star. 14.3 88.2 42.1 83.4
3 Port 15.2 87.7 42.1 83.4
4 Star. 15.0 88.7 42.1 84.3
5 Port 30.1 84.7 42.1 85.6
6 Star. 29.3 84.8 42.1 85.6
7 Port 53.8 80.3 42.1 84.4
8 Star. 53 .3 80.4 42.1 84.4
9 Port 53.2 81.0 42.1 85.2
10 Star. 53.8 80.8 42.1 84.9
1 1 Port 31.6 84.8 42.1 86.1
12 Star. 29.4 84.7 42.1 85.5

90
m 88
> 86 ,
T l slope: -3.9 dBA/doubling
g 34 1 standard deviation: 0.5 dBA
a. ,_
-o 1 ,
82 a, X l T
x x 1 ,1
x ..
LT
80 T T T T T . T I
10 12.5 20 25 30 40 50 60 70

Logarithmic Distance (in)
Figure 32: Test #7 Field Data, Measured SPLS (Gland Standard Deviation- and Error

Compensated-Corrected (X) SPLS and Predicted SAE J 34 SPL (—) with Reflect to ma
Measured SPLs Best-fit Logarithmic Reggession Line (—)

 

78

Test Number: 8

Hull Identification: MC 1 2448.1
Boat Operator: Mike Savara
Data: 9-10-2005

Mp: Torch Lake, MI

Comments: 27' formula, twin 280HP, 350 cubic inch, out drive. This data set is NOT
used because it was interrupted by a thunderstorm.

Trial # Boat Minimum Distance Maximum SPL Measured Background Corrected

Star. 14.9 77.4 34.4 72.8
Port 14.8 76.7 34.4 72.1
Star. 14.4 77.9 34.4 73.0
Port 14.4 78.2 34.4 73.3
Star. 27.8 73.0 34.4 73.3
Port 28.2 73.0 34.4 73.3

 

  

 
     

 

79
, I
l; 1' “T
> 75 1 1;,
h ' (T
a 73 ...' 1,3,. slope: -4.9 dBA/doubling
1‘ '11 standard deviation: 0.4 dBA
[T x
8 71 1 §x 1
1 X
69 -f“" “ _E " ’ ’ ”"1"""" [1‘ '_'— F‘MW "P—"""7—”_"1
10 12.5 20 25 30 40 50 60 70

anrithmic Distancg (m)
Figure 33: Test #8 Field Data, Measured SPLS (OLand Staflard Deviation- and Error

Compensated-Corrected (X) SPLflnd Predicted SAE J 34 SPL (—) with Respect to the
Measured SPLs Best-fit Logarithmic Regression Line (—)

79

Test Number: 9

Hull Identification: MC6546ST
Boat Operator: Jeremy Howard
page; 9-10-2005

LoLtion: Torch Lake, MI

Comments: Unmodified 2005 Jetski, Yamaha VX110 Sport, 1100cc. This data set is
NOT used because it is not considered a motorboat.

Table 12: Test #9 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Trial # M Minimum Distance Maximum SPL Measured Background Corrected
_ Side Measured (in) Measured (dBA) Norse SPL (dBA) SPL (dBA)
1 Star. 9.9 83.6 48.6 75.3
2 Port 12.8 82.3 48.6 76.3
3 Star. 11.8 82.7 48.6 76.0
4 Port 11.1 82.8 48.6 75.5
5 Star. 24.2 77.5 48.6 76.7
6 Port 24.0 77.5 48.6 76.7
7 Star. 24.6 80.1 48.6 79.7
8 Port 24.6 77.7 48.6 77.1
9 Star. 50.8 69.6 48.6 71.9
10 Port 49.4 68.6 48.6 70.8
1 1 Star. 49.3 70.1 48.6 73.2
12 Port 49.1 69.3 48.6 71.4
13 Star. 11.8 82.5 48.6 75.8

 

 

 

 

 

 

 

 

 

 

 

 

 

  
  

 

 

 

 

84 d
80 —
76 , .
: slope. -6.2 dBA/doubling
x X X 1 LT standard deviation: 1.4 dBA
X 4 T
72 T TT
1 T
L;
68 f T T T T T T T
10 12.5 20 25 30 40 50 60 70

Logarithmic Distance (m)
F'gge 34: Test #9 Field Data, Meaflred SPLS (Gland Standard Deviation- and Error

Compensated-Corrected (X) SPLS and Predicted SAE J 34 SPL (—) with Respect to the
Measured SPLS Best-fit Logarithmic Regression Line (—)

80

Test Number: 10

Hull Identification: MC3529PB

Boat Operator: Heather Wilson, sheriffs dept.
Oat_e: 9-10-2005

w: Torch Lake, MI

Comments: Antrim County Sheriffs Department Boat; 200 Mercury, 2 stroke, 21.5', DC
Aquasport. This data set is NOT used because of testing interference

Table 13: Test #10 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
    
 

 

 

 

Trial # Boat Minimum Distance Maximum SPL Measuredflickground Corrected
— Side Measured (m) Measured (dBA) Noise SPL (dBA) SPL (dBA)
1 Star. 15.0 78.2 59.5 72.1
2 Port 14.4 77.7 59.5 71.2
3 Star. 14.4 77.1 59.5 70.6
4 Port 14.5 78.1 59.5 71.7
5 Star. 29.7 75.2 59.5 74.5
6 Port 28.3 72.0 59.5 70.2
7 Star. 28.5 71.8 59.5 70
8 Port 27.5 71.5 59.5 68.7
9 Star. 53.1 65.6 59.5 63.9
10 Star. 52.1 65.9 38.4 69.4
1 1 Port 52.6 66.8 38.4 70.5

80
g
_c 76
E _ - _-

72 slope: -6.2 dBA/doubling
h , g), 1 standard deviation: 1.3 dBA
3 68 - . l x
5: l T X
s: 64 y 1 ‘
m l x

l
60 1 T l l , l
10 12.5 20 25 30 40 50 60 70

Lo a 'thmi Distance m
Figure 35: Test #10 Field Data. Measfured SPLS (Gland Stapcfitrd Deviation- and Error
Compenaated-Corrected (X) SPLS and Predicted SAE J 34 SPL (—) with Respect to the

Measured SPLS Best-fit Logarithmic Reggession Line (—)

 

81

Test Number: 11

Hull Identification: MC2209RZ

Boat Operator: John Roberts

Data: 9-10-2005

anti_o_n_: Torch Lake, MI

Comments: Powerquest 7.4 liter, all stock, 26', Legend SX

Table 14: Test #11 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  
 

 

 

Trial # _Bo_at Minimum Distancg Maximum SPL Measured Backgrpund Correc
— Side Measured1m) Measured(dBA) Norse SPL (dBA) SPL(dBA) 1
1 Port 14.3 91.6 26.5 86.8
2 Star. 17.8 91.7 26.5 88.8
3 Port 13.5 91.6 26.5 86.3
4 Star. 14.1 91.5 26.5 86.6
5 Port 14.2 90.1 26.5 85.2
6 Star 28.2 84.9 26.5 85.5
7 Port 27.7 84.9 26.5 85.5
8 Star. 53.0 80.5 26.5 84.8
9 Port 52.2 80.4 26.5 84.6
10 Star. 53.2 80.5 26.5 84.8
11 Port 52.2 81.0 26.5 85.2
12 Port 16.0 88.6 54.2 84.5
13 Port 28.2 85.0 54.2 85.3
14 Port 27.6 84.5 54.2 84.7
92 e
88
L, ______ __ _ ___- ._
'7 .; slope: -5.6 dBA/doubling
,3 g; g standard deviation: 1.0 dBA
"' 84 x (5.1
x *i >K
x * 3' x
1
80 T T iT T T T T
10 12.5 20 25 30 40 50 60 70

ngarithmig Qigtance (m)

Figge 36: Test #11 Field Data, Meaflred SPLs (o) and Standard Deviation- and Error
Compensated-Corrected (X) SPLaand Predicted SAE J 34 SPL (—) with Reflect to the

 

Measured SPLs Best-fit Logarithmic Reggession Line (—)

82

Test Number: 12

Hull Identification: MC7243PL

Boat Operator: Scott Kowalski

Drag: 9-10-2005

may; Torch Lake, MI

Comments: Sunsation, 24', BravoOne, 502 cubic inch, 400HP

Table 15: Test #12 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

   

 

  

 

 

Trial # Boat Minimum Distancg Maximum SPL Measured Backggound Corrected
—— % Measured (m) Measured (dBA) Noise SPL (dBA) SPL (dBA)
1 Star. 18.4 90.7 47.0 88
2 Port 29.8 87.3 47.0 88.2
3 Star. 32.5 87.2 47.0 88.6
4 Port 33.3 86.5 47.0 88
5 Star. 15.8 92.0 47.0 88.1
6 Port 14.5 91.8 47.0 87
7 Star. 55.6 82.0 47.0 86.3
8 Port 52.2 81.5 47.0 85.4
9 Star 53.1 82.6 47.0 86.6
10 Port 51.6 83.4 47.0 87.3
1 1 Star 14.6 92.9 47.0 88.3
12 Port 13.7 92.4 47.0 87.2
96 --
92 —
>
88 7'": slope: -5.3 dBA/ddubling
x x x 1 standard deviation: 0.6 dBA
X x l i
34 _ TT
1 'T
1;:
30 T T T T T T T
10 12.5 20 25 30 40 50 60 70

Logarithmic Distance (m)
Figu_re 37: Test #12 Field Data, Measured SPLs (OLand Standard Deviation— and Error

Compensated-Corrected (X) SPLS and Predicted SAE J 34 SPL (—) with Rgaect to the
Measured SPLaBest-fit Logarithmic Regression Line (—)

 

83

Test Number: 13

Hull Identification: MC7243PL

Boat Operator: Scott Kowalski

Dfi: 9-10-2005

L_oc_atio_n_: Torch Lake, MI

Comments: Sunsation, 24', BravoOne, 502 cubic inch, 400HP, * Captain's Choice

Table 16: Test #13 Noise Gun Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
  
 

 

 

 

Trial # Baa; Minimum Distange Maximum SPL Measured Backgropnd mg
_ Side Measured (in) Measured (dBA) Noise SPL (dBA) SPL (dBA)
1 Star. 15.5 78.1 39.6 73.7
2 Port 14.5 77.1 39.6 72.1
3 Star. 15.1 80.1 39.6 75.7
4 Port 29.1 72.9 39.6 73.4
5 Star. 28.4 74.6 39.6 75.0
6 Port 27.7 72.9 39.6 73.2
7 Star. 54.2 68.4 39.6 72.3
8 Port 53.1 67.6 39.6 71.4
9 Star. 51.7 68.8 39.6 72.1
10 Port 51.9 66.5 39.6 70.2
11 Port 14.3 76.5 39.6 71.4
12 Star. 27.6 75.5 39.6 75.7
84 ~ “'5
1 1
80 --T
76 *
slope: -5.5 dBA/doubling
72 7 standard deviation: 1.4 dBA
x I 1
x
68 I
1 l l
64 . T i” '1 T T T r T
10 12.5 20 25 30 40 50 60 70

o a ' i Di n e m
Figme 38: Test #13 Field Data, Measured SPLS (o) and Standard Deviation- and Error
Compensated-Corrected (X) SPLs and Predicted SAE J 34 SPL (—) with Respect to the
Measured SPLs Best-fit Logarithmic Reggession Line (—)

 

84

Test Number: 14

Hull Identification: MC5326LK
Boat Operator: Rick Godden

Date: 9-10-2005

Location: Torch Lake, MI

Comments: Sea Ray, 26', 260HP, 350 cubic inch, through prop exhaust, 2 small block

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

      

 

 

Chev.
Table 17: Test #14 Noise Gun Readout
Trial # Boat Minimum Distancg Maximum SPL Measured Background Corrected
—— _S_l_L1§ Measured (in) Measured (dBA) Noise SPL (dBA) SPL (dBA)
1 Star. 13.8 73.9 40.8 68.5
2 Port 16.1 73.5 40.8 69.5
3 Port 29.4 68.6 40.8 69.0
4 Star. 26.5 69.6 40.8 69.4
5 Port 54.9 66.7 40.8 70.7
6 Star. 54.5 66.0 40.8 70.0
7 Star. 14.5 78.9 40.8 73.9
8 Port 27.5 74.3 40.8 74.5
9 Star. 27.4 74.0 40.8 74.2
10 Port 52.4 68.6 40.8 72.3
1 1 Star. 52.9 70.5 40.8 74.5
80
O I T
T T
76 T T":
> o 0 13:1 9
72 T x T: x
1:.1
11°
68 _T X 1" 1x 0
x ! l slope: -4.l dBA/doubling 0
64 L1 standard deviation: 2.3 dBA .
. l l l l . . 7
10 12.5 20 25 30 40 50 60 70

L ar' i istanem

Figm 39: Test #14 Field Data, Measured SPLS (o) and Standard Deviation- and Error
Commnsated-Corrected (X) SPLS and Predicted SAE J 34 SPL (—) with Re§pect to the

Measured SPLs Best-fit Logarithmic Reggession Line (—)

85

Test Number: 15

Hull Identification: MC2103PB

Boat Operator: Jason McCaleb

%: 9-10-2005

L_oc_am: Torch Lake, MI

Comments: Aquasport, 21.5', 200HP Mercury outboard, 2 stroke

Table 18: Test #15 Noise G_1._ln Readout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  
  

 

 

 

Trial # Boat Minimum Distance Maximum SPL Measured Background Corrected
— Side Measured (m) Measured (dBA) Noise SPL (dBA) SPL (dBA)
1 Port 12.6 77.7 32.0 71.8
2 Star. 10.7 75.2 32.0 67.8
3 Port 12.4 76.8 32.0 70.7
4 Star. 25.7 69.9 32.0 69.7
5 Port 26.1 72.4 32.0 72.5
6 Star. 25.8 70.0 32.0 69.9
7 Port 25.6 72.6 32.0 72.6
8 Star. 51.5 64.0 32.0 67.8
9 Port 50.6 65.0 32.0 68.7
10 Star. 51.3 64.9 32.0 68.7
1 1 Port 50.4 65.0 32.0 68.7
12 Star. 11.9 74.0 32.0 67.5

80 .
1 T
T( 0
an
76 -4
>
72 ~
slope: -5.2 dBA/doubling
68 _ standard deviation: 1.5 dBA
x x l ’
L1
64 T T T T .9 T T
10 12.5 20 25 30 40 50 60 70

Lpgarithmic Distange (r_n_)

Figpre 40: Test #15 Field Data, Measured SPLS (O) and Standard Deviation- and Error
Compensated-Corrected (X) SPLS anfid Predicted SAE J 34 SPL (—) with Respect to the

Measured SPLs Best-fit Logarithmic Reggession Line (—1

86

 

Appendix F:
Correction Calculation Comparison

87

 

Test Number: 1

Hull Identificartion: MC4728SJ
Boat Op_erator: (not recorded)
Die; 7-19-2005

Dom: Higgins Lake, MI

Comments: This data set is NOT used in the analysis due to the different device
calibration between this data set and the Torch Lake data sets.

Table 19: Test #1, Device Corrected SPL Approximation Compared to the Actual Decimal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Calculation
Minimum Maximum Measured Corrected Correct_T_e_d_ Corrected
rial # Distance $1, Background SPL on SE; SPL
L Measured Measured Noise SPL Device Calgulatiop Differgpcg
(pi) (dBA) (dBA) (dBA) (dBA) (dBA)
1 52.6 78.1 52.7 81.8 81.9 -0.1
2 53.4 75.8 52.7 79.4 79.5 -0.1
3 51.4 80.6 52.7 84.2 84.4 -0.2
4 53.7 78.6 52.7 82.5 82.6 -0.1
5 26.1 82.9 52.7 82.8 82.9 -0.1
6 27.0 80.5 52.7 80.7 80.6 0.1
7 27.5 83.0 52.7 83.2 83.3 -0.1
8 27.1 81.4 52.7 81.3 81.5 -0.2
9 26.5 67.6 52.7 65.4 66.2 -0.8
10 27.5 81.1 52.7 81.1 81.3 -0.2
11 16.4 80.9 52.7 76.8 76.9 -0.1
12 28.4 66.0 52.7 64.2 64.6 -0.4
13 15.4 83.1 52.7 78.6 78.6 0.0
14 15.1 81.6 52.7 76.8 76.9 -0.1
15 15.4 71.8 52.7 65.9 66.6 -0.7
16 15.2 81.2 52.7 76.4 76.6 -0.2
17 14.9 70.7 52.7 65.7 65.1 0.6
18 14.8 70.7 52.7 65.7 65.0 0.7

 

 

 

 

 

 

 

 

88

Test Number: 2

Hull Identification: MC8487SV
Boat Operator: (not recorded)
Data: 7-19-2005

Dacatiap: Higgins Lake, MI

Comments: This data set is NOT used in the analysis due to the different device
calibration between this data set and the Torch Lake data sets.

flble 20: Test #2. Device Corrected SPL Approximation Compared to the Actual Decimal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9W
Minimum Maximum Measured Corrected Corrected Corrected
Trial # Distance _S_PL Background SPL op S_P_L £131,
_ Measured Measured Noise SPL Device Oalcplatiop i ce
(an) (dBA) (dBA) (dBA) (dBA) (dBA) 1
1 30.6 67.5 51.3 66.9 67.2 —0.3
2 27.6 66.6 51.3 65.4 65.5 -0.1
3 29.0 65.9 51.3 64.2 65.0 -0.8
4 20.3 68.2 51.3 64.7 65.1 -0.4
5 15.7 70.2 51.3 64.5 65.1 -O.6
6 15.5 70.2 51.3 64.4 65.0 -O.6
7 14.6 69.9 51.3 63.6 64.2 -O.6
8 15.1 69.9 51.3 63.9 64.5 -0.6
9 50.9 61.8 51.3 62.6 62.8 -0.2
10 51.8 62.0 51.3 62.9 63.2 -0.3
11 51.3 60.4 51.3 60.1 60.8 -0.7
12 52.1 61.9 51.3 62.8 63.1 -0.3
13 51.7 60.1 51.3 59.9 60.4 -O.5
14 51.5 62.2 51.3 63.0 63.5 -0.5

 

 

 

 

 

 

 

 

 

 

 

 

 

89

Test Number: 3

Hull Identification: MC4387PE
Boat Operator: (not recorded)
Data: 7-19-2005

Miran: Higgins Lake, MI

Comments: This data set is NOT used in the analysis due to the different device
calibration between this data set and the Torch Lake data sets.

Table 21: Test #3. Device Corrected SPL Approximation Compared to the Actual Decimal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Calculation

Minimum Maximum Measured Corrected Correcte_d Corrected

Trial # Distance S_P_L Backgrouna SPL op Sfl, OE;
— Measured Measure Noise SPL Devica Oalaulation Djfl‘gapaa

(m) (dBA) (dBA) (dBA) (QBA) (dBA)

1 50.9 58.8 51.3 56.9 58.1 -1.2

2 50.3 62.5 51.3 63.2 63.7 -0.5

3 24.8 66.5 51.3 64.8 64.8 0.0

4 26.9 65.7 51.3 63.6 64.3 -0.7

5 12.9 71.2 51.3 63.8 64.5 -0.7

6 12.1 71.2 51.3 63.2 64.0 -0.8

7 50.3 60.7 51.3 60.3 61.1 -0.8

8 50.1 61.9 51.3 62.6 62.9 0.3

9 25.2 67.1 51.3 65.4 65.6 -0.2

10 26.8 65.5 51.3 63.4 64.0 -0.6

11 12.6 71.2 51.3 63.6 64.3 -0.7

12 14.2 69.8 51.3 63.2 63.8 -0.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

90

 

Test Number: 4

Hull Identificatpipz MC3706PB

Boat Operator: Tim Tilley

Dag: 9-10-2005

Map: Torch Lake, MI

Comments: Antrim County Sheriffs Department Boat; Twin 150HP Evinrude 2 stroke

Table 22: Test #44 Device Corrected SPL Approximation Compared to the Actual Decimal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Calculation
Minimum Maximum Measured Corrected Corrected Corrected
Trial # Distance SD; Background SPL on SfiL SPL
-— Measured Msured Noise SPL Device Calculation Differenca
(m) (dBA) (dBA) (dBA) (dBA) (dBA) 1
1 17.6 80.4 32.6 77.4 77.3 0.1
2 31.4 77.5 32.6 78.7 78.8 -0.1
3 14.7 82.9 32.6 78.3 78.3 0.0
4 56.5 71.6 32.6 76.2 76.2 0.0
5 25.7 78.0 32.6 78.1 78.1 0.0
6 12.9 81.2 32.6 75.5 75.4 0.1
7 52.7 72.1 49.4 75.6 75.7 -0.1
8 52.6 71.1 32.6 75.0 75.3 -0.3
9 13.4 81.9 49.4 76.2 76.3 -0.1
10 26.5 76.0 49.4 75.8 75.9 -0.1
11 51.1 70.3 49.4 72.7 73.6 -0.9
12 26.7 75.5 49.4 75.4 75.4 0.0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

91

 

Test Number: 5

Hull Identification: MC3457SN
Boat Operator: Bill Johnson
Data: 9-10-2005

Mp: Torch Lake, MI

Comments: Yellow Catamaran dual hulls; 900HP, 4 stroke, V8 supercharge Teague,
Gatling mufflers. This data set is NOT used because there weren't enough trials.

Table 23: Test #5, Device Corrected SPL Approximation Compared to the Actual Decimal

 

 

 

 

 

 

 

 

Calculation
Minimum Maximum Measured Corrected Corrected Corrected
Trial # Distance .S_PL Backgroppa SPL an fl SPL
_ Measured Maa_sure_d Noise SPL Deviaa Qalculatiop Di cu
(m) (dBA) (dBA) (dBA) (dBA) (dBm 1

1 40.4 101.0 32.7 103.0 103.8 -0.8

2 46.5 98.0 32.7 101.0 101.6 -0.6

3 65.3 97.4 32.7 102.0 102.9 -0.9

4 74.7 93.5 32.7 99.8 99.8 0.0

5 28.3 101.0 32.7 101.0 101.7 -0.7

6 44.7 92.6 32.7 95.9 95.9 0.0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

92

 

Test Number: 6

Hull Identification: MC3529PB

Boat Operator: Heather Wilson, sheriffs dept.
Dari: 9-10-2005

1.0—cam: Torch Lake, MI

Comments: Antrim County Sheriffs Department Boat; 200 Mercury, 2 stroke, 21.5', DC
Aquasport. This data set is NOT used because of possible wind effects.

Lable 24: Test #6, Device Corrected SPL Approximation Compared to the AM Decimal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Calculation

Minimum Maximum Measured Corrected Corrected Corrected

Trial # Distance 2; Background SPL on E: _S_E_L
_ Measured Measured Noise SPL Device Calculaaiop Difference

(m (dBA) (dBA) (dBA) (dBA) (dBA)

1 14.6 72.8 44.2 67.7 67.8 -0.1

2 18.7 79.2 55.6 75.9 76.1 -0.2

3 14.8 81.6 55.6 76.6 76.6 0.0

4 16.6 79.7 55.6 75.4 75.6 -0.2

5 15.5 81.6 55.6 77.0 77.0 0.0

6 32.1 73.4 55.6 73.1 73.6 -0.5

7 31.5 75.2 55.6 74.8 75.6 -0.8

8 29.9 74.9 55.6 74.2 74.9 ~0.7

9 54.6 68.8 55.6 70.8 71.2 -0.4

10 55.5 69.5 55.6 71.6 72.1 -0.5

11 53.1 67.2 55.6 68.2 68.9 -0.7

12 53.0 69.4 55.6 71.2 71.8 -0.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

93

Test Number: 7

Hull Identification: MC3220RP

Boat Operator: Bill Johnson

%: 9-10-2005

L_oc_atiap: Torch Lake, MI

Comments: 2 H8500 Birkhauser formula 350, 35.5', F ASTech

Table 25: Test #7,I Device Corrected SPL Approximation Compared to the Actual Decimal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Calculation
Minimum Maximum Measured Comamd Corrected Corrected
Trial # Distance SPL Background SPL op SE; S_PI_.
‘— Measured Measured Noise SPL Devica Oalculation Ditfgenaa
(r_n_) (dBA) (dBA) (dBA) (dBA) (dBA)
1 13.4 88.0 42.1 82.6 82.6 0.0
2 14.3 88.2 42.1 83.4 83.3 0.1
3 15.2 87.7 42.1 83.4 83.3 0.1
4 15.0 88.7 42.1 84.3 84.2 0.1
5 30.1 84.7 42.1 85.6 85.7 -0.1
6 29.3 84.8 42.1 85.6 85.7 -0.1
7 53.8 80.3 42.1 84.4 84.6 -0.2
8 53.3 80.4 42.1 84.4 84.7 -0.3
9 53.2 81.0 42.1 85.2 85.3 -0.1
10 53.8 80.8 42.1 84.9 85.1 -0.2
11 31.6 84.8 42.1 86.1 86.1 0.0
12 29.4 84.7 42.1 85.5 85.6 -0.1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

94

Test Number: 8

Hull Identification: MC 1 244SJ
Boat Operator: Mike Savara
M: 9-10-2005

Loam: Torch Lake, MI

Comments: 27' formula, twin 280HP, 350 cubic inch, out drive. This data set is NOT
used because it was interrupted by a thunderstorm.

Table 26: Test #8. Device Corrected SPL Approximation Compared to the Actual Decimal

 

 

 

 

 

 

 

 

 

Calculation
Minimum Maximum Measured Corrected Corrected Corrected
rial # Distance _S_P_L Backgigound SPL an S_PL SPL.
L— Measured Measure Noise SPL Deviae Oalculation Differanaa
(m) (dBA) (dBA) (dBA) (dBA) (dBA)
1 14.9 77.4 34.4 72.8 72.9 -0.1
2 14.8 76.7 34.4 72.1 72.1 0.0
3 14.4 77.9 34.4 73.0 73.1 -0.1
4 14.4 78.2 34.4 73.3 73.4 -0.1
5 27.8 73.0 34.4 73.3 73.5 -0.2
6 28.2 73.0 34.4 73.3 73.6 -0.3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

95

Test Number: 9

Hull Identification: MC6546ST

Boat Operator: Jeremy Howard

M: 9-10-2005

_Iacaaop: Torch Lake, MI

Comments: Unmodified 2005 Jetski, Yamaha VXl 10 Sport, 1100cc. This data set is

NOT used because it is not considered a motorboat.

Table 27 : Test #9, Device Corrected SPL Approximation Compared to the Actual Decimal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9.4m

Minimum Maximum Measured Corrected Corrected Corrected
Trial # Distance 3; Background SPL on _SLL SPL

Measured Measured Noise PL Devica Calculation Differgca

(m) (dBA) (dBA) (dBA) (dBA) (dBA) 1
1 9.9 83.6 48.6 75.3 75.4 -0.1
2 12.8 82.3 48.6 76.3 76.3 0.0
3 1 1.8 82.7 48.6 76.0 76.0 0.0
4 11.1 82.8 48.6 75.5 75.6 -0.1
5 24.2 77.5 48.6 76.7 76.9 -0.2
6 24.0 77.5 48.6 76.7 76.8 -0.1
7 24.6 80.1 48.6 79.7 79.7 0.0
8 24.6 77.7 48.6 77.1 77.3 —0.2
9 50.8 69.6 48.6 71.9 72.9 -1.0
10 49.4 68.6 48.6 70.8 71.6 -0.8
11 49.3 70.1 48.6 73.2 73.3 -0.1
12 49.1 69.3 48.6 71.4 72.4 -1.0
13 11.8 82.5 48.6 75.8 75.8 0.0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

96

 

Test Number: 10

Hull Identification: MC3529PB

Boat Operator: Heather Wilson, sheriffs dept.
Dari: 9-10—2005

Dam: Torch Lake, MI

Comments: Antrim County Sheriffs Department Boat; 200 Mercury, 2 stroke, 21.5', DC
Aquasport. This data set is NOT used because of testing interference.

Table 28: Test #10, Device Corrected SPL Approximation Compared to the Actual

Dacimal Calculation
Minimum Maximum Measured Corrected Conecjal Corrected
Distance 3; Background SPL op fill SPL,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M Measured Measured Noise SPL Device Calculation Difference
(_tp) (dBA) (dBA) (dBA) (dBA) (dBA)
1 15.0 78.2 59.5 72.1 72.7 -0.6
2 14.4 77.7 59.5 71.2 71.8 -0.6
3 14.4 77.1 59.5 70.6 71.1 -0.5
4 14.5 78.1 59.5 71.7 72.3 06
5 29.7 75.2 59.5 74.5 74.6 -0.1
6 28.3 72.0 59.5 70.2 70.4 -0.2
7 28.5 71.8 59.5 70.0 70.1 -0.1
8 27.5 71.5 59.5 68.7 69.5 -0.8
9 53.1 65.6 59.5 63.9 64.0 -0.1
10 52.1 65.9 38.4 69.4 69.8 -0.4
1 1 52.6 66.8 38.4 70.5 70.8 —0.3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

97

 

Test Number: 11

Hull Identification: MC2209RZ

Boat Operator: John Roberts

Da_te_: 9-10-2005

Laaapap: Torch Lake, MI

Comments: Powerquest 7.4 liter, all stock, 26', Legend SX

_Table 29: Test #11. Device Corrected SPL Approxmtion Corppared to the Actual

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D_ecima1 Calculation
Minimum Maximum Measured Corrected Corrected Corrected
Trial # Distance S_PL Background SPL on _S_flla 1521,
_ Measured Measured NOise PL Devica Calculation Differance
(m) (dBA) (dBA) (dBA) (dBA) (dBA)
1 14.3 91.6 26.5 86.8 86.8 0.0
2 17.8 91.7 26.5 88.8 88.8 0.0
3 13.5 91.6 26.5 86.3 86.3 0.0
4 14.1 91.5 26.5 86.6 86.5 0.1
5 14.2 90.1 26.5 85.2 85.2 0.0
6 28.2 84.9 26.5 85.5 85.6 -O.1
7 27.7 84.9 26.5 85.5 85.5 0.0
8 53.0 80.5 26.5 84.8 84.8 0.0
9 52.2 80.4 26.5 84.6 84.6 0.0
10 53.2 80.5 26.5 84.8 84.8 0.0
11 52.2 81.0 26.5 85.2 85.2 0.0
12 16.0 88.6 54.2 84.5 84.6 -0.1
13 28.2 85.0 54.2 85.3 85.4 -0.1
14 27.6 84.5 54.2 84.7 84.8 -0.1

 

 

 

 

 

 

 

 

 

 

 

 

 

98

 

Test Number: 12

Hull Identifica_ticai_: MC7243PL

Boat Operator: Scott Kowalski

m: 9-10—2005

L_ocflap: Torch Lake, MI

Comments: Sunsation, 24', BravoOne, 502 cubic inch, 400HP

Table 30: Test #12. Device Corrected SPL Approximation Compared to the Actual
Dacimal Calculation
Minimum Maximum Measured Corrected Oorrected orrected

Trial # Distance SPL Background SPL op 53L SPL
— Measured Maasured Noise SPL Device Oalculatian Differanaa

(mi (dBA) (dBA) (dBA) (dBA) (dBA) 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 18.4 90.7 47.0 88.0 88.0 . 0.0
2 29.8 87.3 47.0 88.2 88.2 0.0
3 32.5 87.2 47.0 88.6 88.6 0.0
4 33.3 86.5 47.0 88.0 88.1 -0.1
5 15.8 92.0 47.0 88.1 88.0 0.1
6 14.5 91.8 47.0 87.0 87.0 0.0
7 55.6 82.0 47.0 86.3 86.5 -O.2
8 52.2 81.5 47.0 85.4 85.6 -0.2
9 53.1 82.6 47.0 86.6 86.8 -0.2
10 51.6 83.4 47.0 87.3 87.4 -0.1
11 14.6 92.9 47.0 88.3 88.2 0.1
12 13.7 92.4 47.0 87.2 87.1 0.1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

99

 

Test Number: 13
Hull Identification: MC7243PL

Boat Operator: Scott Kowalski
Date: 9- 10-2005

Location: Torch Lake, MI
Comments: Sunsation, 24', BravoOne, 502 cubic inch, 400HP, * Captain's Choice

Table 31: Test #13. Device Corrected SPL Approximation Compared to the Actual
Dacimal Calculation
Minimum Maximum Measured Corrected Correctad Corrected

Trial # Distanca 21 Background SPL ap SPL SPL
— Measured Measured Noise SPL Device Oalculation Differenca

(m) (dBA) (dBA) (dBA) (dBA] (dBé)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 15.5 78.1 39.6 73.7 73.9 -0.2
2 14.5 77.1 39.6 72.1 72.3 -0.2
3 15.1 80.1 39.6 75.7 75.7 0.0
4 29.1 72.9 39.6 73.4 73.6 -0.2
5 28.4 74.6 39.6 75.0 75.2 -0.2
6 27.7 72.9 39.6 73.2 73.3 -0.1
7 54.2 68.4 39.6 72.3 72.5 -0.2
8 53.1 67.6 39.6 71.4 71.6 -0.2
9 51.7 68.8 39.6 72.1 72.7 -0.6
10 51.9 66.5 39.6 70.2 70.3 -0.1
11 14.3 76.5 39.6 71.4 71.5 -0.1
12 27.6 75.5 39.6 75.7 75.9 -0.2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

100

 

Test Number: 14

Hull Identifica_tiop: MC5326LK
Boat Operator: Rick Godden
Data: 9-10-2005

m: Torch Lake, MI

Comments: Sea Ray, 26', 260HP, 350 cubic inch, through prop exhaust, 2 small block
Chev.

 

Table 32: Test #14, Device Corrected SPL Approximation Compared to the Actual
Decimal Calculation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Minimum Maximum Measured Corrected Corrected Corrected
Trial # Distanca 511: Background SPL on 51’; ,S_PL
Measured Measured Noise SPL Device Oalaulatiop W
m) (dBA) (dBA) (dBA) (dBA) (dBA)
1 13.8 73.9 40.8 68.5 68.6 -0.1
2 16.1 73.5 40.8 69.5 69.5 0.0
3 29.4 68.6 40.8 69.0 69.2 -0.2
4 26.5 69.6 40.8 69.4 69.6 -0.2
5 54.9 66.7 40.8 70.7 70.8 -0.1
6 54.5 66.0 40.8 70.0 70.0 0.0
7 14.5 78.9 40.8 73.9 74.1 -0.2
8 27.5 74.3 40.8 74.5 74.7 -0.2
9 27.4 74.0 40.8 74.2 74.3 -0.1
10 52.4 68.6 40.8 72.3 72.5 -0.2
1 1 52.9 70.5 40.8 74.5 74.5 0.0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

101

 

Test Number: 15

Hull Identification: MC2103PB

Boat Operator: Jason McCaleb

Data: 9-10-2005

Lam: Torch Lake, MI

Comments: Aquasport, 21.5', 200HP Mercury outboard, 2 stroke

file 33: Test #15. Device Corrected SPL Approximation Cormpared to the Actual

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Decimal Calcu latiop
Minimum Maximum Measured Corrected Corrected Corrected ,-
Trial # Distance 2; Background SPL on _S_P_L S_PL
—— Measured Measured Noise SPL Device Calculation Differenca "
(m) (dBA) (dBA) (dBA) (dBA) (dBA) 1
1 12.6 77.7 32.0 71.8 71.7 0.1
2 10.7 75.2 32.0 67.8 67.8 0.0
3 12.4 76.8 32.0 70.7 70.7 0.0 a;
4 25.7 69.9 32.0 69.7 69.9 -0.2
5 26.1 72.4 32.0 72.5 72.6 -0.1
6 25.8 70.0 32.0 69.9 70.1 -0.2
7 25.6 72.6 32.0 72.6 72.7 -0.1
8 51.5 64.0 32.0 67.8 67.9 -0.1
9 50.6 65.0 32.0 68.7 68.9 -0.2
10 51.3 64.9 32.0 68.7 68.8 -0.1
11 50.4 65.0 32.0 68.7 68.8 -0.1
12 11.9 74.0 32.0 67.5 67.5 0.0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

102

Appendix G:
Analysis of SAE J34 Distance Acceptability

103

 

Table 34: Analysis of SAE J34 Distance Table 38: Analysis of SAE J34 Distance

Distance by SAE J34
Measured Standard?

Distance by SAE J34
Measured Standard?

Trial #

   

Table 35: Analysis of SAE J 34 Distance Table 39: Analysis of SAE J34 Distance

Distance by SAE J34
Measured Standard?

Distance by SAE J34

M Measured Standard?

   

Table 36: Analysis of SAE J 34 Distance Table 40: Analysis of SAE J34 Distance

Distance bySAEJ34 Trial# Distance by SAEJ34
Measured Standard? — Measured Standard?

 

Table 37: Analysis of SAE J34 Distance

Distance by SAE J34

m Measured Standard?

 

104

Works Cited

105

 

ANSI S 1.4-1983, 1983, Specification for Sound Level Meters, American National
Standards Institute

ANSI 81.42-2001, 2001, Design Response of Weighting Networks for Acoustical
Measurements, American National Standards Institute

Applied Dynamic Measurements, A [WV-3 3-Channel Acoustic Weighting Network Data
Sheet, North Beach, Australia

Hubele, N., Montgomery, D., and Runger, G., 2001, Engineering Statistics, John Wiley
& Sons, Inc., New York, pp. 66-67, A—3

ICOMIA 45-98, 1991, Determination of Reference Boat Parameters for Sound 1"—
Emissions, International Council of Marine Industry Associations

ISO 14509, 2004, Small crafi - Measurement of Airborne Sound Emitted by Powered
Recreational Craft, International Organization for Standardization,

 

ISO 226:2003, 2003, Acoustics — Normal Equal-Loudness-Level Contours, International
Organizations for Standardization

 

Lanpheer, R., 1987, Powerboat Sound Level Engineering Report, National Marine
Manufacturers Association

Lanpheer, R., 1993, Recreational Motorboat Sound Level Test Report. ICOMIA Marine
Environment Committee

Lanpheer, R., 2000, Pleasure Motorboat Model Noise Act

Marine Safety Act, 1994, Natural Resources and Environmental Protection Act,
Legislative Council, State of Michigan

Pierce, AD, 1981, Acoustics, an Introduction to Its Physical Principles and Applications,
McGraw-Hill Inc, New York, NY, pp. 39, 42, 61

 

Radcliffe, C.J., 2002, Sound Propagation and Measurement in an Open Space
Environment, personal correspondence

SAE J 1970, 1991, Shoreline Sound Level Measurement Procedure, Society of
Automotive Engineers

SAE 12005, 1991, Stationary Sound Level Measurement Procedure for Pleasure
Motorboats, Society of Automotive Engineers

SAE J 34, 2001, Exterior Sound Level Measurement Procedure for Pleasure Motorboats,
Society of Automotive Engineers

Vidanage, S., 2003, Digital Sound Meter for Moving Vehicles, M .S. Thesis, Michigan
State University

http://www.icomia.com/about-icomia/introduction.asp, International Council of Marine
Industry Associations website

106

http://www.iso.org/iso/en/aboutiso/introduction/index.htrnl, International Organization
for Standardization website

www.michigan.gov/dnr/, Michigan Department of Natural Resources website

www.sae.org/about, Society of Automotive Engineers website

107

 

 

 

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