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Nov 1982

Volume 72, Issue S1, pp. S1-S108

Page 1 of 21 Pages Return to All Sections Next Page
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back to top Session A. Underwater Acoustics I: The Impact of Satellite and Aerial Remote Sensing on the Study of Ocean Acoustics
Invited Papers
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Ocean features observed from manned spacecraft that influence acoustics in the upper ocean (A)

Robert E. Stevenson

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S1-S1 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Ocean fronts, eddies, and internal waves have been observed, photographed, and imaged by synthetic aperture radar during the first four orbital missions of the space shuttle, Columbia. Supporting data show that the visual features correspond to thermal discontinuities, have significant vertical extensions, act as barriers to underwater acoustics, and can be detected by synthetic aperture radar regardless of sky conditions or time of day. Although one thinks of these sea‐surface manifestations as having a certain ubiquity, presently available information seems to show that they are concentrated both generically and geographically. This concept is to be addressed from Columbia and Challenger during 1983.
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Connection between acoustic and electromagnetic sea‐surface backscatter (A)

Suzanne T. McDaniel

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S1-S1 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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The performance of active high‐frequency acoustic systems operating under water is, in many cases, limited by backscattering from the sea surface. The strength of surface reverberation has been experimentally found to depend on the speed of the wind driving the ocean waves, while the Doppler spread of the scattered signals has been related to the waveheight. Electromagnetic sea‐surface backscatter may be used to remotely sense the ocean surface and, hence, provides a means of empirically predicting the properties of acoustic reverberation. We investigate the relationship between acoustic and electromagnetic surface backscatter. The physical mechanisms responsible for acoustic backscatter are discussed and the extent to which the relevant oceanic parameters may be extracted from electromagnetic backscatter data is assessed. It is concluded that electromagnetic remote sensing of the ocean surface provides a viable means of predicting both the strength and Doppler characteristics of underwater reverberation.
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Prediction of ambient noise in the deep ocean from surface wind data obtained via satellite (A)

D. Shonting

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S1-S1 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Open ocean measurements at both shallow and deep depths show that ambient acoustic noise above 10–15 kHz increases nearly linearly as the log of the wind speed. This relationship is studied under a variety of wind/sea conditions at 15, 20, and 25 kHz bands using a newly developed self‐contained ambient noise recorder (SCANR). Assessment is made of possible ambient noise prediction from wind speed data obtained from a satellite mounted microwave scatterometer.
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Satellite remote sensing and underwater acoustics: What you see is not necessarily what you get (A)

Robert F. Henrick and Charles L. Johnson

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S2-S2 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Continuing efforts in satellite systems and analysis methodology may soon result in routine production of ocean weather maps for substantial regions of the world's oceans. Such maps might illustrate positions of such mesoscale features as ocean fronts and eddies and be available to the acoustician on a routine basis. (In fact such products are presently available for the Gulf Stream region.) However, the use of such maps without guidance as to the acoustic significance of these features may have limited utility to an acoustician deciding on the deployment of an acoustic system, and may indeed serve to mislead. A front or eddy that may be clearly visible to a satellite sensor may not be acoustically significant to the system under consideration. Even if the mesoscale feature has acoustic impact, the surface expression of the feature may not coincide with the acoustically important portion of the feature. Alternately, acoustically relevant mesoscale anomalies may not be visible to a satellite sensor. To illustrate these cautions, oceanographic data taken by the U.S. Naval Oceanographic Office Ocean Measurements Program in the Northeast Atlantic and Norwegian Sea are utilized in conjunction with numerical acoustic propagation simulations. This region is typical of areas where significant mesoscale activity occurs and oceanographic sampling is sparse, so that satellite remote sensing may be very useful in predicting acoustic system performance. However, examples presented illustrate that significant work must be done before a useful satellite oceanographic product can be turned into a useful acoustic product. [Work supported by the U.S. Naval Oceanographic Office.]
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SAW's, the connection between space and hydrophones (A)

Paul A. Nysen

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S2-S2 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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SAW (Surface Acoustic Wave) devices are a new class of signal processing and signal generating elements now in use with radar and communication systems. These devices can be made as filters, delay lines, or resonators which are small, rugged, and inexpensive. This paper discusses the mechanical and thermal sensitivities of SAW's with a view towards using these properties to sense temperature, pressure, and sound in water. Various modulation schemes are examined. Finally a buoy system is explored, involving a gauge string of SAW hydrophones/temperature/pressure sensors which can be enabled and interrogated from a space platform.
Contributed Papers
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The use of satellite data for the detection and estimation of large acoustic anomalies caused by ocean currents (A)

James V. White and Robert F. Brammer

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S2-S2 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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The Seasat‐A satellite carried a radar altimeter and a microwave scatterometer that provided nearly global data sets on sea surface height, significant wave height, and sea‐surface wind velocity. These data, and similar data from future satellite missions, can be used to estimate ocean parameters that effect underwater sound generation, propogation, and surface scattering. This paper describes a matched‐filter technique for using altimeter data to detect, locate, and estimate the sizes of large coherent acoustic anomalies caused by mesoscale (50 km–500 km) rotating current rings. These ring currents are spawned by the Gulf Stream, have lifetimes ranging from several months to two years, and produce characteristic sea‐surface height signatures in the altimeter data. A technique for processing the altimeter data to estimate sound‐speed profiles in cold‐core current rings is discussed, and results for representative ring currents are presented.
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Satellite detection of anomalies in ocean ambient noise? (A)

Calvin R. Dunlap and Glenn H. Jung

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S2-S2 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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ASTREX (Acoustic Storm Response Experiment) observations made in mid‐November 1980, along a flight line from Cape Mendocino, California, toward the central Gulf of Alaska, included concurrent airborne expendable bathythermograph (AXBT) measurements of surface and sub‐surface temperatures and ambient noise measurements (1–2000 Hz) using sonobuoys, with hydrophones deployed at 400 ft (122 m). NOAA‐6 satellite infrared observations also were available. It is shown that anomalous (low) ambient noise values, measured at 122 meters and frequencies 500–2000 Hz, appear to be associated with a warm‐core eddy extending from the surface to depths greater than 250 m. This thermal feature is shown clearly at the sea surface in a satellite infrared photograph. It appears that the warm‐core eddy had refracted ambient noise away from the hydrophone, since ambient noise levels are several decibels higher outside the eddy region. It is suggested that careful studies are warranted of relations between ambient noise, thermal structure, and surface temperature features detectable by satellite, exploring the possibility of using satellites in some circumstances to indicate subsurface ambient noise anomalies.
back to top Session B. Architectural Acoustics I: The Technical Committee on Architectural Acoustics V. O. Knudsen Distinguished Lecture
Invited Paper
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Complexity and contradiction in proscenium theater design—The last one hundred years (A)

George C. Izenour

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S3-S3 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Proscenium theater design, rooted in Baroque tradition of court theater design and Beaux Arts architectural design achieved apogee in Opera de Paris (1875). Bayreuth Festpielhaus (1876) touched off a controversy in theater design among architecture, engineering, and artistic style that persists to this day. Opera de Paris was the last theater of historical importance where the architect alone made all crucial design decisions. Bayreuth Festpielhaus was the first theater of historical significance where the architect shared responsibility for design and technology with a theater consultant. At the time there was no such thing as an acoustical consultant. The ensuing century (1880–1980) changed everything. The industrial revolution changed structure and added mechanical and electrical engineering to the building process. Sabine provided the method for acoustical predesign of interior spaces. Post W.W. II computer revolution provided sophistication of operation. Mechanized transportation changed forever the relation of theater buildings to the overall fabric of urban design. These disparate disciplines have each contributed to the complexity of design and execution of theater buildings and the still unresolved artistic styles have all together become the modus operandi of contemporary theater design. It is for reasons both of a program dictating multiple use and the sheer magnitude of the engineering solutions resulting therefrom that apogee of proscenium theater design for our time will have been consumated in Teatro Teresa Carrena to be opened in Caracas, Venezuela (1983).
Contributed Papers
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Acoustical modeling of Troy Music Hall (A)

D. P. Ayyappan

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S3-S3 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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An acoustical model built to a scale of 1:16 was utilized in evaluating the acoustics of the Troy Music Hall in Troy, New York. The model was modified into different configurations to identify the specific physical characteristics of the hall that might aid the acoustical qualities of the hall. Technical limits and usefulness of an acoustical model to determine the probable acoustical qualities of concert halls at an early stage were evaluated by comparing the objective qualities in the model and in its prototype. The initial assumption involves the accepted high quality of Troy Music Hall. It was found that an acoustical model is an effective research tool, within limitations, in probing the early energy components. The objective data obtained from the model studies coincide, in general, with the subjective qualities found in the hall. The model study shows that the first balcony in the Troy Music Hall receives an equal distribution of lateral and non‐lateral energies in the first 80 ms.
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A sonic tour of symphonic concert halls (A)

J. Robert Ashley

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S3-S3 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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The Koss CM‐1030 speakers designed by the author will be described to justify their choice for the demonstration at the 104th meeting. The 100‐liter bass section was synthesized to a 30‐Hz BB4 alignment. Dual closed‐box 800 ml mid‐range systems are crossed over at 300 Hz. Dome tweeters cover the spectral ranges of 2 to 6 to 15 kHz. These speakers have much lower intermodulation distortion than most commercially marketed speakers. Telarc® digitally mastered recordings will be used for most of the sonic examples. These recordings have been made with three omni‐directional microphones and little equalization. A recording from the current best concert hall in the world, Powell Hall in St. Louis, will illustrate the accuracy of the recording and playback process. Another good hall, Symphony Hall in Boston, will show why the musicians prefer halls such as these. The cold, steely string quality of many modern halls will be sonically illustrated by the Atlanta Symphony. Slides will illustrate the physical causes of sonic differences.
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Effects of auditorium acoustics on musical performance (A)

John Charles Cox

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S3-S3 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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The echo perception thresholds of listeners and performers are compared. Performer's minimum detectable delay (MDD) and maximum tolerable delay (MTD) are presented. The effects of several auditoria on the performers of music are shown.
back to top Session C. Noise I and CCEA: The National Noise Control Program: Needs and Strategies
Invited Papers
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Transportation noise: The federal viewpoint (A)

John E. Wesler

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S4-S4 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Over the past year and one‐half, the Federal program for transportation noise control has undergone a number of changes, both in direct and overall policy. Transportation noise control remains an important priority, especially since public reaction to transportation noise severely constrains the efficient growth of a national transportation system needed to meet forecast demands for the movement of people and goods. In some cases, noise is forcing reductions in system capacity, directly in the face of demands for system expansion. This paper will review recent changes in Federal noise control programs and policies, and will attempt a brave look into the future of those activities.
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Proposed noise strategy for commercial aircraft (A)

Richard J. Linn

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S4-S4 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Since recent court rulings have given the local airport proprietor more responsibility in reducing noise in airport communities without being discriminatory to any one airline, and in light of the continued difficulty in achieving federal pre‐emption, this paper will present a strategy for achieving meaningful noise reduction without undo legislation by governing bodies.
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The national noise control program: needs and strategies; motor vehicle noise: the industry viewpoint (A)

Paul P. Pataky

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S4-S4 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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This presentation briefly describes the history of the motor vehicle industry's involvement in the understanding and control of transportation noise and, specifically, the impact of motor vehicle noise on overall community noise levels. Recognizing the need for valid noise regulations, the presentation then discusses industry's requirement for harmonized vehicle noise standards and test procedures in order to facilitate compliance to those regulations in the most cost‐effective manner possible. The paper then presents industry's recommendations for future strategies that can be implemented to meet the objective of achieving a quieter environment at the least cost to society. These strategies include the use of computer mathematical models to determine the environmental impact of new vehicle noise regulations and to assess other, perhaps more viable and more cost‐effective alternatives to vehicle noise regulations. Also discussed are strategies that can be pursued jointly by industry, the voluntary standards associations and the motor vehicle regulators to achieve harmonization of motor vehicle noise standards and compliance test procedures, not only on a national, but on a worldwide basis.
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Noise, land use planning and the HUD noise policy (A)

Richard H. Brown

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S4-S4 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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As opportunities for additional significant reductions in major noise sources decrease, land use planning remains one of the few ways to prevent noise problems from developing. The HUD noise policy specifically encourages communities to consider noise in their land use planning. It is not, however, the total answer by any means. There will always be situations where other local priorities must take precedence, particularly in urban areas. Noise attenuation measures will continue to be important and a crucial part of the HUD noise policy. Lacking any specific legislative authority on general land use issues, the Federal role can only be to encourage local governments to consider noise in their land use planning process and to provide information.
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The national noise control program: Needs and strategies—State and local perspectives (A)

Jesse O. Borthwick

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S5-S5 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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On October 1, 1982, the U.S. Environmental Protection Agency's noise control program came to an end. The program was phased out following a determination by the Reagan Administration that, “the benefits of noise control can be adequately carried out at the State and local level without the presence of a federal program.” This decision to defederalize noise control has raised many questions concerning the further roles and needs of state and local noise control programs, such as: What actions will the states and cities take in the area of new product noise regulation, and how will these actions affect industry? Where will noise control officials be able to turn for technical and financial assistance? The author will discuss these and other questions currently confronting state and local noise control professionals.
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European commissions' noise abatement action program—A global approach on an international level (A)

J. M. Junger

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S5-S5 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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The purpose of this paper is to indicate the role of the EEC's Action Programme for Noise Abatement, to present its evolution and to place it in the context of the European Community. It is also intended more particularly to discuss the interaction between this programme and (1) the national, regional, or local programs; (2) the global economic interests, which result from the free circulation of goods and a reduced distortion of competition; (3) energy saving. In conclusion, it is attempted to point at some criteria which might possibly constitute a basis for a coordinated noise abatement policy at an international level. The key word will be “harmonization” which must be understood as an optimal relationship between different components of a whole.
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Voluntary noise standards to meet national needs (A)

Kenneth McK. Eldred

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S5-S5 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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The apparent termination of a federal noise control program in the Environmental Protection Agency removes a potential for a coordinated Federal leadership in the field of environmental noise in the USA, except for the areas in which authority is vested in other Federal agencies, such as the Department of Transportation, Defense, Labor, and Housing and Urban Development. At the same time the needs for control of various aspects of environmental noise persist both here and throughout the world. It may be anticipated that many states and localities will attempt to meet some of these needs through regulations and other activities. The the extent that these regulations and controls require measurement, harmonization of noise scales and measurement procedures is required, if the result is to be nonchaotic. This paper gives a brief overview of the extent of the potential impacts of various parts of the environmental noise problem in terms of sound exposure and population exposed. It then addresses the potential roles and interaction between sound and operating controls and summarizes their current status with respect to the various parts of the environmental noise problem. From this summary it deduces the needs for measurement procedures and their harmonization, and explores the possible roles of the voluntary standards sector in fulfilling these needs.
back to top Session D. Physiological Acoustics I: Peripheral Acoustics and Physiology
Contributed Papers
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The influence of the sound level of a steady‐state broadband noise on the temporal response of the acoustic reflex (A)

Nicole Lalande and Raymond Hétu

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S6-S6 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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The influence of the sound level of a steady‐state pink noise on the short‐ and the long‐term response of the contralateral acoustic reflex was investigated with nine adult subjects. Three noise levels were selected (LpA of 95, 100, and 110) for a duration of 16 min (or 8 min occasionally). Based on previous data [R. H. Wilson et al., J. Acoust. Soc. Am. 64, 782–791 (1978)], it was hypothesized that when the reflex activity is expressed in absolute value of change in acoustic susceptance, the reflex decay is the same whatever the intensity of the noise; expressed in relative value of percentage of change in susceptance, the reflex adaptation is greater for a low level of noise than for higher ones. Results clearly confirmed the above hypothesis. These findings explain the conflicting results previously obtained in terms of the way data are analyzed. Practical implications concerning the protection afforded by the acoustic reflex under such noise exposures will be discussed.
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The importance of external and middle ear contributions to bone conduction in man (A)

S. Gatehouse

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S6-S6 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Differences between air conduction (a–c) and bone conduction (b–c) thresholds are commonly used to determine the presence and magnitude of a middle ear abnormality in the human audiotory system, making the tacit assumption that b–c directly stimulates the cochlea. Animal experiments have long established that b–c transmission is a complex phenomenon [J. Tonndorf, in Foundations of Modern Auditory Theory, Vol. 2 (Academic, New York, 1972)] with significant contributions from middle and external ear components. An artificial reversible middle ear abnormality may be induced in man by maintaining an air pressure in the external meatus. The shifts in a–c and b–c thresholds provide a means to evaluate the relative importance of the external and middle ear components. At the lower frequencies of 250 and 500 Hz, these components predominate; at 500 Hz there is an a–c shift of 15.9 dB accompanied by a b–c shift of 15.8 dB. These results have important implications for the interpretation of air and bone conduction thresholds.
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Ear‐canal resonances and the assessment of hearing thresholds at high frequencies (A)

K. N. Stevens, S. H. Blumenthal, D. M. Green, and M. Krasner

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S6-S6 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Standing waves in the ear canal cause substantial difficulties in the assessment of high‐frequency (8000–20 000 Hz) hearing thresholds because of uncertainties in the specification of the acoustic stimulus. A calibration procedure is proposed for estimating the sound prcssure p1 at the inner end of the ear canal by measuring the poles of the impulse response at the entrance to the ear canal when an acoustic source is coupled directly to the canal through a short tube. This calculation is based on the fact that the transfer function from the source to p1 is an all‐pole function. As a step towards implementation of this procedure, frequencies and bandwidths of ear‐canal resonances for a number of ears have been measured. The data show that these resonances have bandwidths as small as 300 Hz, and deviations from equal spacing that are usually no greater than 10%. The pressure p1 has been calculated from the appropriate all‐pole transfer function, and shows systematic and predictable differences with measured peak sound pressures in the outer 1 to 1.5 cm of the ear canal, as expected on the basis of measurements with models. [Supported by a contract from NINCDS.]
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Electrical stimulation of the auditory nerve: Membrane models applied to the interpretation of electrophysiological and psychophysical responses (A)

M. White and M. Merzenich

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S6-S6 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Electrophysiological and psychophysical measures of threshold as a function of sinusoidal stimulus frequency deviate considerably from those predicted by Hill's membrane model. Using a modified Hodgkin‐Huxley model, considerably better estimates of threshold were obtained over the frequency ranges investigated. The Hodgkin‐Huxley model was modified by increasing the sodium inactivation rate constant, beta‐h, by a factor of four. This model has been useful in interpreting electrophysiological and psychophysical responses to a range of pulse and sinusoidal stimuli. [Work supported by NIH.]
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Ear‐canal acoustic emissions as frequency‐specific indicators of cochlear function (A)

Richard A. Schmiedt and Cheryl L. Addy

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S6-S6 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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Acoustic emissions in the form of distortion products (2f1‐f2) can be measured in the external ear canal. Previous work has shown that the nonlinearities generating these emissions reside in the cochlea and disappear with metabolic disruption. Distortion products measured in the cochlear microphonic and in the responses of auditory‐nerve fibers have been shown to be generated largely at the cochlear location associated with the primary tones. If cochlear emissions behave similarly, it should be possible to generate an “acoustic‐emission audiogram” with appropriately placed primary pairs; i.e., low‐frequency pairs could be used to test the cochlear apex, high‐frequency pairs to test the base. We have obtained acoustic‐emission and whole‐nerve action potential audiograms in Mongolian gerbils and cats both before and after exposure to narrow‐band noise sufficient to cause a temporary threshold shift. Our results indicate that emssions produced by lower‐level primaries (70 db SPL) seem to reflect the recovery of the whole‐nerve response over time better than higher‐level primaries (80 dB SPL). Further, acoustic emissions can be used on a frequency‐specific basis to monitor the condition of the mid and basal regions of the cochlea. [Work supported in part by a South Carolina Biomedical Research Grant.]
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Acoustic and auditory nerve measurements of distortion products (A)

P. F. Fahey and J. B. Allen

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S6-S7 (1982); (2 pages)

Online Publication Date: 12 Aug 2005

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We have made measurements of distortion products responses in the ear canal and in the auditory nerve of the cat. The frequencies and levels of the primaries, f1 and f2, were varied in such a way that the frequency and level of the distortion product, as measured by the response of a neuron at its threshold, were held constant. In particular, we found, as has been previously reported by others, that the amplitude of the primaries needed to give an isoresponse was relatively independent of frequency for the f2‐f1 signal and strongly frequency dependent for the 2f1‐2f2 signal. The level and frequency dependence of the distortion product 2f1‐f2 as measured in the ear canal (which were not seen when the driver was terminated with an acoustic cavity) seem to agree with the level and frequency dependence of the distortion products that were detected by single neurons in the auditory nerve.
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Phase and group delay in the auditory nerve relative to the cochlear microphonic (A)

J. B. Allen

J. Acoust. Soc. Am. Volume 72, Issue S1, pp. S7-S7 (1982); (1 page)

Online Publication Date: 12 Aug 2005

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We have extended our earlier measurements of cochlear phase response by measuring the round window potential phase, which is then used as a reference phase. This normalization greatly simplifies the phase and group delay because it appears to remove middle ear artifacts. After being normalized, the group delay shows a monotonically increasing delay with increasing frequency. This data seems to be inconsistent with a large class of “second filters.”
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