APPENDIX F
NOISE INFORMATION
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A. Glossary of Noise Terms
Ambient Noise Level The prevailing or energy-average noise level in an area comprised
of all sounds from near and far. Usually described by the Leq or an
Hourly Leq-based sound descriptor such as Ldn.
CNEL
Community Noise Equivalent Level. Used in the State of
California. Similar to the DNL (Ldn), this descriptor is an annual
measure of cumulative noise exposure in a community where a
penalty is applied during nighttime hours (10:00 pm to 7:00 am) to
account for increased sensitivity to noise at night. This time
weighting is applied by adding 10 dBA to the measured level of all
dBA
Decibel
sound that occurs during the nighttime period. The CNEL
additionally applies a penalty during evening hours (7:00 pm to
10:00 pm) to account for increased sensitivity to noise during these
hours. This “time weighting” is applied by adding 5 dBA to the
measured level of all sound that occurs during the evening period.
Decibels, A-weighted, referring to overall decibels of a sound
where the strength of its individual frequencies have been modified
by applying the "A scale” such that the lower and very high
frequencies are discounted. A dBA value presents the sound level
containing a range of frequencies weighted in a manner
representative of the human hearing response to the typical
intensity of common environmental sound.
A unit of measurement on a logarithmic scale that describes the
magnitude of a particular quantity of sound pressure with respect
to a standard reference pressure value of 20 micropascals. The
perceived loudness of a sound corresponds to its absolute
magnitude compared to the reference sound or to the magnitude of
other sounds. Decibels may also be used to describe other ratiobased quantities such as Sound Power Level, Sound Intensity
Level, or various vibration levels.
DNL
Frequency
See Ldn.
The number of times per second that the sine wave of sound repeats itself,
or that the sine wave of a vibrating object repeats itself. Frequency
is expressed in cycles per second and is abbreviated as Hertz (Hz).
The frequency corresponds to the perceived pitch of a sound (e.g.,
high or low).
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Hourly Noise Level
Insertion Loss
Leq
HNL, see Leq, (h).
IL. A measure, expressed in decibels, of the acoustical
effectiveness of any sound barrier to reduce/abate the sound
pressure level experienced at a Receiver location. The IL value is
subtracted from the unabated sound level that would occur at the
Receiver location to determine the final, abated sound level.
Energy-equivalent sound level. The equivalent continuous nonvarying sound level calculated to occur during a stated period, that
contains the same acoustical energy as a time-varying sound
occurring (or predicted to occur) during the same period. The Leq is
computed by summing the noise energy during the stated period
using mathematical integration.
Leq(h)
Energy-equivalent noise level for a one-hour period. Sometimes
referred to as Hourly Noise Level.
Ldn
Day-Night Average Sound Level. An annual measure of
cumulative noise exposure in a community that applies a penalty
Ln
Noise
Receiver, Receptor
Source
during nighttime hours (10:00 pm to 7:00 am) to account for
increased sensitivity to noise at night. The time weighting is
applied by adding 10 dBA to the measured level of all sound that
occurs during the nighttime period.
The “statistical” sound level equaled or exceeded "n" percent of
the time during a measurement. For example, L10 is the sound level
equaled or exceeded 10% of the time, or for 6 minutes during a
one-hour period. The L50 would represent the sound level exceeded
for 30 minutes during a 60-minute period.
Unwanted sound. Based on subjective human individual or group
assessment of a given sound’s interference, annoyance, loudness,
inappropriateness, etc.
A location (potentially) affected by noise. Receivers refer to both
modeling locations and monitoring locations that are selected
because of their sensitivity to noise and/or because they are
representative of other sensitive uses.
Sound Source. Typically a vehicle, machinery, or other device that
generates high levels of sound that is considered noise by
Receivers.
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Additional sound descriptors and terms may be found in publications of the American
National Standards Institute (e.g., ANSI S1.1-1994 and ANSI S12.9-1988, Reaffirmed
September 1998). An extensive Glossary of Acoustic terms prepared by the Institute of
Noise Control Engineering of the United States may be found at
http://users.aol.com/inceusa/glossary.html.
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B. California Department of Motor Vehicle Noise Regulations
Table F-A-1 California Department of Motor Vehicles Noise Limits for Highway
Vehicles
My CA
This Site
Vehicle Registration and Sale Prohibitions
27200. (a) The Department of Motor Vehicles shall not register on a dealer's report of sale a new motor vehicle,
except an off-highway motor vehicle subject to identification as provided in Division 16.5 (commencing with Section
38000), which produces a maximum noise exceeding the applicable noise limit at a distance of 50 feet from the
centerline of travel under test procedures established by the Department of the California Highway Patrol.
(b) The Department of Motor Vehicles may accept a dealer's certificate as proof of compliance with this article.
(c) Test procedures for compliance with this article shall be established by the Department of the California Highway
Patrol, taking into consideration the test procedures of the Society of Automotive Engineers.
(d) No person shall sell or offer for sale a new motor vehicle, except an off-highway motor vehicle subject to
identification as provided in Division 16.5 (commencing with Section 38000), which produces a maximum noise
exceeding the applicable noise limit specified in this article, and for which noise emission standards or regulations
have not been adopted by the Administrator of the Environmental Protection Agency pursuant to the Noise Control
Act of 1972 (P.L. 92-574).
(e) No person shall sell or offer for sale a new motor vehicle, except an off-highway motor vehicle subject to
identification as provided in Division 16.5 (commencing with Section 38000), which produces noise that exceeds or in
any way violates the noise emission standards or regulations adopted for such a motor vehicle by the Administrator of
the Environmental Protection Agency pursuant to the Noise Control Act of 1972 (P.L. 92-574).
(f) As used in this section, the term "register" is equivalent to the term "licensing" as used in Section 6(e)(2) of the
Noise Control Act of 1972 (P.L. 92-574).
Amended Ch. 558, Stats. 1977. Effective January 1, 1978.
Limits for Vehicles Exceeding 5,999 Pounds Gross Vehicle Weight
27204. For the purposes of Section 27200, the following noise limits shall apply to any motor vehicle within the
specified manufacturer's gross vehicle weight rating and date of manufacture:
GVWR-Pounds
Date of Manufacture
Noise Limit -dbA
Over 6,000
after 1967 and before 1973
88
Over 6,000
after 1972 and before 1975
86
Over 6,000
after 1974 and before 1978
83
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Over 8,500
after 1977 and before 1982
83
Over 6,000 but not over 8,500
after 1977
80
Over 8,500 but not over
10,000
after 1981
80
Over 10,000
after 1981 and before 1988
83
Over 10,000
after 1987
80
Amended Ch. 274, Stats. 1985. Effective January 1, 1986.
Limits for Other Vehicles
27206. For the purposes of Section 27200, the following noise limits shall apply to any other motor vehicle, not
specified in this article, manufactured:
(1) After 1967, and before 1973
86 dbA
(2) After 1972, and before 1975
84 dbA
(3) After 1974
80 dbA
Amended and renumbered Ch. 558, Stats. 1977. Effective January 1, 1978.
Limit for Governor-Equipped Vehicles Exceeding 10,000 Pounds
27207. No motor vehicle with a gross vehicle weight rating of more than 10,000 pounds and equipped with an
engine speed governor shall produce a sound level exceeding 88 dbA, measured on an open site at a distance of 50
feet from the longitudinal centerline of the vehicle, when its engine is accelerated from idle with wide open throttle to
governed speed with the vehicle stationary, transmission in neutral, and clutch, if any, engaged. Test procedures for
compliance with this section shall be established by the department, taking into consideration the procedures of the
United States Department of Transportation. The procedures may provide for measuring at other distances, in which
case the measurement shall be corrected so as to provide for measurements equivalent to the noise limit established
by this section measured at 50 feet.
Amended Sec. 134, Ch. 124, Stats. 1996. Effective January 1, 1997.
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C. Noise Barrier Information
Table F-B-1 Characteristics of Common Rigid Noise Barrier Materials
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D. Sample of Reduced Noise Construction Equipment
The following information is representative of available construction equipment that has
noise reduction designs and/or features to provide equipment that is appreciably and
demonstrably quieter than standard equipment. The information is not a specific
endorsement of a particular model or brand and is not considered exhaustive. Equipment
from other manufacturers may provide equivalent or better acoustical performance.
Table F-D-1 Noise limits for special vehicles, heavy equipment, and construction
machinery
Above Ground Equipment
Lmax dBA @ 50
Equipment
ft
AIR COMPRESSOR(E) 650CFM W/RECIEVER
68
AIR COMPRESSOR(D) 175CFM
68
GENERATOR, DIESEL-POWERED, 1500KWH
73
Mfg.
Model
Sullair
600H
Sullair
210H
Cummins
DFLE
Reference Level from NYC
DEP Shaft 33B EIS and from
EPA, 1971
Vantage
Lincoln Electric
400
Vantage
Lincoln Electric
400
Reference Lmax from Boston
Big Dig Project
DUMP TRUCK, WATER TRUCK, BACKHOE,
GRADER
76
WELDERS (E) 400A
68
WELDER(D) 400A
68
AUGER DRILL FOR SECANT PILES
(OPTIONAL)
85
EXCAVATOR, CAT 345
85
Reference Lmax from Boston
Big Dig Project
4 CY CLAM BUCKET
95
Reference Lmax from Boston
Big Dig Project
WHEEL LOADER CAT966 W/ FORK
79
SKID STEER LOADER BOBCAT
Reference Lmax for Front End
Loader from RCNM
Equipped with Noise
Reduction Package option
Approximate from EPA, 1971
Reference Lmax from Boston
Big Dig Project
GROUT PUMP CG600
75
CONCRETE PUMP TRUCK
82
PILE DRIVER, FOR SHEET PILE (OPTIONAL)
105
From various references; will
consult with Owner regarding
pile driving
CRAWLER CRANE 150TON
81
Reference Lmax for Crane
from RCNM
79
Reference Lmax for
Ventilation Fan from RCNM
VENT FAN
RCNM is Federal Highway's Construction Noise Model
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Sullair Compressors:
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Cummins DFLE 1500 kW Generator:
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Lincoln Electric Vantage 400:
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FHWA Highway Construction Equipment Noise Levels:
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