appendix f noise information

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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

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.

dBA 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.

Decibel 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 ratio-

based quantities such as Sound Power Level, Sound Intensity

Level, or various vibration levels.

DNL See Ldn.

Frequency 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 HNL, see Leq, (h).

Insertion Loss 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.

Leq Energy-equivalent sound level. The equivalent continuous non-

varying 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

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.

Ln 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.

Noise Unwanted sound. Based on subjective human individual or group

assessment of a given sound’s interference, annoyance, loudness,

inappropriateness, etc.

Receiver, Receptor 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.

Source 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



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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 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

Equipment Lmax dBA @ 50

ft Mfg. Model

AIR COMPRESSOR(E) 650CFM W/RECIEVER 68 Sullair 600H

AIR COMPRESSOR(D) 175CFM 68 Sullair 210H

GENERATOR, DIESEL-POWERED, 1500KWH 73 Cummins DFLE

DUMP TRUCK, WATER TRUCK, BACKHOE, GRADER

76 Reference Level from NYC DEP Shaft 33B EIS and from EPA, 1971

WELDERS (E) 400A 68 Lincoln Electric Vantage 400

WELDER(D) 400A 68 Lincoln Electric Vantage 400

AUGER DRILL FOR SECANT PILES (OPTIONAL)

85 Reference Lmax from Boston Big Dig Project

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 Reference Lmax for Front End Loader from RCNM

SKID STEER LOADER BOBCAT Equipped with Noise

Reduction Package option

GROUT PUMP CG600 75 Approximate from EPA, 1971

CONCRETE PUMP TRUCK 82 Reference Lmax from Boston Big Dig Project

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

VENT FAN 79

Reference Lmax for Ventilation Fan from RCNM

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:

appendix f noise information

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