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May 1989

Volume 85, Issue S1, pp. S1-S156

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back to top Session R. Noise IV: Environmental Noise and Impact on Hearing
Contributed Papers
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Canadian “National Guidelines for Environmental Noise Control—Procedures and Concepts for the Drafting of Environmental Noise Regulations/By‐laws in Canada.” (A)

Deirdre A. Morison

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S45-S45 (1989); (1 page)

Online Publication Date: 13 Aug 2005

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These National Guidelines have been prepared for legislators at all levels of government, provincial planners, municipalities, consultants, industries, and designers. The intent is to provide a common basis across Canada for the assessment, measurement, and legislative control of environmental noise while, at the same time, providing options to allow flexibility of choice to fit specific needs. The National Guidelines may be adopted or modified, in entirety and in part, into provincial or municipal legislation or into codes of practice. The National Guidelines are divided into two major parts. Part I, Concepts and Procedures, details the various options available in developing a noise control program and includes a section on Land Use Planning and Model Noise Control Legislation presenting sound level objectives and more general bylaws. The second part of the document contains technical reference material, including a section on instrument specification, measurement, and prediction, and another covering noise reduction techniques. Terms and interpretations, references, and technical support documents are included also. The texts of the technical support documents are briefly summarized in the document and are reproduced on microfiche at the end of the National Guidelines. The National Guidelines were prepared by the Working Group on Environmental Noise on the Federal/Provincial Advisory Committee on Environmental and Occupational Health, which intends to provide periodic revisions.
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Public reaction to low levels of aircraft noise (A)

John E. Wesler

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S45-S45 (1989); (1 page)

Online Publication Date: 13 Aug 2005

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Several recent instances have raised the issue of public annoyance from the noise of airplanes flying at relatively high altitudes or at relatively large distances from the nearest airport. Public complaints have arisen about airplane flights over northern New Jersey as the result of changes in flight patterns associated with the major New York airports, even though in many instances those airplanes are flying at 15 000 ft or higher. Concerns have arisen regarding the noise levels on the ground from the new, swept‐blade, advanced turboprop airplanes when they are flying at cruise altitudes of 30 000 ft and higher. Complaints about aircraft noise over national parks have resulted in a Congressional requirement to measure those noises and determine their severity. These noise levels do not meet the usual criteria for annoyance or interference with individual activity, whether in terms of average level or single events. A better understanding of the intrusive effects of low levels of community noise is needed, especially where present in areas of relatively low ambient noise levels.
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The noise environment under low‐altitude, high‐speed military aircraft training routes (A)

Kenneth J. Plotkin and Alton Chavis

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S45-S45 (1989); (1 page)

Online Publication Date: 13 Aug 2005

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Low‐altitude, high‐speed training operations are routinely conducted along specially designated Military Training Routes (MTRs). Design of new routes and/or realignment of existing routes requires an environmental assessment to determine the community noise impact. Nominally, aircraft on these routes navigate from point to point along defined segments. Key elements required for noise prediction are the frequency of flights, the statistical variation of position relative to the nominal centerline, and the operational noise emission levels of the aircraft. Noise measurements were conducted on three routes: one operated by the Strategic Air Command and two by the Tactical Air Command. On each route, 20 automatic noise monitors were deployed on a 2‐ to 4‐mi array across the route centerline. Major findings were: noise emission levels are fully consistent with predictions from USAF's NOISEFILE database; aircraft tend to fly within the central part of a route; aircraft follow nominal tracks corresponding to defined route centerline or corresponding to prominent visual references; the lateral distribution about each track is Gaussian; and multiple tracks can exist. Noise events were infrequent (typically less than three or four per day), and the highest Ldn measured was less than 65 dB. [This work was sponsored by USAF AAMRL/BBE.]
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ROUTEMAP model for predicting aircraft noise exposure along military training routes (A)

Michael J. Lucas and Kenneth J. Plotkin

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S45-S45 (1989); (1 page)

Online Publication Date: 13 Aug 2005

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A model and PC‐based computer program has been prepared to calculate noise levels along low‐altitude, high‐speed military training routes. The program is designed for use by environmental planning personnel who are familiar with MTR operations and with noise, but are not necessarily expert. The program provides options for selecting general types of operations (visual or instrument navigation), aircraft types and speeds, altitudes, and nominal track centerlines. Up to 20 track/altitude/aircraft types may be defined within a 20‐mi‐wide corridor. Aircraft on each track have a Gaussian lateral distribution about the centerline. The program contains nominal standard deviations based on the type of operations, or the user may specify a site‐specific value. Aircraft noise emission levels are derived from the USAF NOISEFILE database. The program calculates Leq, Ldn, and Ldnmr, where Ldnmr is Ldn with an adjustment to account for the onset rate of MTR aircraft noise. Program output is available in tabular form or in graphs suitable for inclusion in reports. [This work was sponsored by USAF AAMRL/BBE.]
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Sonic boom spectra of Atlantis landing 6 December 1988 (A)

Robert W. Young and Frank T. Awbrey

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S45-S46 (1989); (2 pages)

Online Publication Date: 13 Aug 2005

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After circling the world 69 times, orbiter Atlantis came to a stop on Runway 17 of Edwards Air Force Base in California, at 1537U on 6 December 1988. Some 10 mi to the west, and 4 min previous to landing, its 394‐ms sonic boom swept over our measurement site at latitude 34.886°N, longitude 118.036°W, elevation about 2.5 kf above sea level. When the decelerating Atlantis heading southeast passed nearest to the microphones at lateral slant range of 100 kft, it was gliding at Mach 1 about 48 kft above ground. The peak flat sound pressure level of the sonic boom was 129 dB; the peak C‐weighted sound pressure level, 125 dB; the peak A‐weighted sound pressure level, 110 dB. The flat sound exposure level was 118 dB; the C‐weighted and A‐weighted sound exposure levels of the initial transients were, respectively, 102 and 84 dB. If sound exposure level is wanted for a 400‐ms sonic boom with primary emphasis in the range 0.8–3 Hz, flat sound exposure level is appropriate; with primary emphasis in the range 10–50 Hz, C‐weighted sound exposure level is appropriate; with primary emphasis in the range 80–1000 Hz, A‐weighted sound exposure level is appropriate.
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Revision of a dosage‐effect relationship for the prevalence of noise‐related annoyance (A)

Sanford Fidell

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S46-S46 (1989); (1 page)

Online Publication Date: 13 Aug 2005

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More than a decade has passed since Schultz (1978) derived a relationship between noise exposure and the prevalence of annoyance from the findings of various social surveys of community response to general transportation noise sources. Numerous measurements of the prevalence of noise‐related annoyance have been published in subsequent years. A least‐squares quadratic fitting function to a set of 427 data points (developed by addition of 266 new data points to the original set of 161 data points) differs little from the third‐order polynomial fit to the original data set. [Work supported by U.S. Air Force Noise and Sonic Boom Impact Technology Program under Contract F33615‐86‐C‐0530.]
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Effects of changing the A‐weighting design goal (A)

George S. K. Wong

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S46-S46 (1989); (1 page)

Online Publication Date: 13 Aug 2005

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The proposal by the International Organization for Standardization (ISO), document ISO/TC43/SCI N644, dated October 1988, to modify the A‐weighted design goal by imposing additional attenuation to implement well‐defined frequency cutoffs at 20 Hz and at 16 kHz to ensure consistent A‐weighted measurements is examined. The merit of the above proposal is in doubt since the high‐frequency cutoff at 16 kHz eliminates both audible and high‐frequency components and can result in underestimation during A‐weighted noise assessment, particularly when the noise is impulsive. The consequences of the above changes are serious: Future databases of A‐weighted measurements will be incompatible with those from the past, and acoustical communities in every country will suffer financial loss due to the need to replace most of their measuring instruments to comply with the proposed A‐weighting. A better approach to ensure consistent A‐weighted measurement is to impose tighter tolerances in the high‐frequency region of the A‐weighting, such as those specified in ANSI S1.4A‐1985 amendment to ANSI S1.4‐1983.
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Sound exposures and hearing thresholds of musicians in a major symphony orchestra (A)

Julia Doswell Royster, Larry H. Royster, and Mead C. Killion

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S46-S46 (1989); (1 page)

Online Publication Date: 13 Aug 2005

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Seventy noise dosimetry samples were obtained for musicians during rehearsals and performances of a major symphony orchestra. Audiograms were obtained for 59 musicians. The Leq during measurement periods ranged from 76–102 dBA (median = 90dBA), corresponding to on‐the‐job daily equivalent values of 72–98 dBA (median = 86 dBA). Using the ISO 1999.2 model, this exposure would be expected to produce 5–8 dB of NIPTS after 30 yr for typical ears (0.5 fractile) or 8–10 dB of NIPTS for very susceptible ears (0.05 fractile). The musicians' average thresholds were better than those for age‐matched reference nonindustrial noise‐exposed populations without occupational noise exposure, and only slightly worse than those for highly screened populations representing aging alone. However, audiogram patterns indicated a slight notch, suggesting a contribution from NIPTS. Bilaterally averaged thresholds for musicians in different instrument sections were essentially equivalent, but violinists and violists grouped together showed significantly poorer thresholds at 2–4 kHz in the left ear than in the right ear. Measured Leq correlated with HTLs at 3–4 kHz. Playing in a symphony orchestra appears to present a mild risk of hearing damage, but musicians in every age group displayed average hearing thresholds better than the general population.
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Review of the effects of noise on performance (A)

Alice H. Suter

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S46-S47 (1989); (2 pages)

Online Publication Date: 13 Aug 2005

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The effects of noise on job performance are not as easily discerned and predictable as other effects, such as those on hearing or speech communication. The extent to which noise affects performance depends on numerous nonacoustical factors, such as the subject's biological and psychological state, as well as certain external factors. Despite these and other difficulties involved in comparing research results, a recent review of the noise and performance literature provides sufficient evidence to indicate adverse effects under certain circumstances. The probability of performance decrements increases with increased (1) noise level, (2) intermittency, (3) aperiodicity, (4) lack of controllability. (5) task complexity, (6) task duration, and (7) the addition of certain other stressors. The review was sponsored by the U.S. Army Human Engineering Laboratory, and performed under the auspices of Gallaudet University.
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Growth of threshold shift from intense impulses: Implications for basic loss mechanisms (A)

G. Richard Price

J. Acoust. Soc. Am. Volume 85, Issue S1, pp. S47-S47 (1989); (1 page)

Online Publication Date: 13 Aug 2005

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For a given number of impulses, increases in intensity are normally associated with greater threshold shifts. The details of this growth should, in principle, reveal something of the basic mechanisms responsible for the loss. Experiments have been conducted in which the ears of 30 cats have been exposed to 50 impulses with their peak energies located at 4000 Hz and with peak pressures ranging from 135–145 dB SPL. Threshold shifts grew about 7.0 dB for every dB increase in SPL above 134 dB. Virtually the same result can be calculated from data for the chinchilla ear [R. P. Hamernik, J. H. Patterson, and R. J. Salvi, J. Acoust. Soc. Am. 81, 1118–1129 (1987)], which may indicate that this function is characteristic of mammalian ears. On the other hand, exposures to other impulses in both animals have shown much lower rates of growth; however, these differences can be explained by conductive nonlinearities in the middle ear and/or a limited range of growth of threshold shift.
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