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Jun 1983

Volume 73, Issue 6, pp. 1897-2251

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Rise–fall time effects on the brainstem auditory evoked response: Mechanisms

Kurt Hecox and Don Deegan

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2109-2116 (1983); (8 pages) | Cited 1 time

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Experiments were conducted to assess the contribution of place mechanisms to the effect of rise–fall time on wave V of the human brainstem auditory evoked response (BAER). Noise bursts of 4‐ and 10‐ms duration were presented at various rise–fall times (0, 1, 2, and 5 ms). Subtractive high‐pass masking techniques were used to determine the effect of rise time as a function of derived‐band frequency. In general, increasing rise time prolonged wave V latency but did not affect amplitude. Rise‐time effects did not depend on derived‐band frequency and similar effects were seen in the unmasked conditions. In addition, narrowing the derived band did not alter the observed effects on latency and amplitude. Signal envelope showed no effects on traveling wave velocity. These results suggest that place mechanisms contribute little to changes in the BAER associated with rise–fall time.
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43.64.Ri Evoked responses to sounds
43.64.Qh Electrophysiology of the auditory central nervous system
43.66.Mk Temporal and sequential aspects of hearing; auditory grouping in relation to music

A general equation describing frequency discrimination as a function of frequency and sensation level

David A. Nelson, Mary E. Stanton, and Richard L. Freyman

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2117-2123 (1983); (7 pages) | Cited 11 times

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Frequency‐discrimination thresholds, for a wide range of stimulus frequencies and stimulus levels, were obtained from three normal‐hearing listeners. Linear regression analyses of the present data, and of data from two previous studies, indicate that an SL−1 transformation of stimulus level and a (F)1/2 transformation of stimulus frequency yield linear dimensions that allow accurate predictions of frequency‐discrimination thresholds from normal‐hearing listeners over a wide range of stimulus frequencies (125–8000 Hz) and stimulus levels (5–80 dB SL) with a single prediction equation.
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43.66.Fe Discrimination: intensity and frequency
43.66.Ba Models and theories of auditory processes
43.66.Lj Perceptual effects of sound

A possible auditory basis for internal structure of phonetic categories

Joanne L. Miller, Cynthia M. Connine, Trude M. Schermer, and Keith R. Kluender

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2124-2133 (1983); (10 pages) | Cited 5 times

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We used a selective adaptation procedure to investigate the possibility that differences in the degree to which stimuli within a phonetic category are considered to be good exemplars of the category—that is, differences in perceived category goodness—have a basis at a prephonetic, auditory level of processing. For three different phonetic contrasts (/b–p/, /d–g/, /b–w/), we assessed the relative magnitude of adaptation along a stimulus continuum produced by a variety of stimuli from the continuum belonging to a given phonetic category. For all three phonetic contrasts, nonmonotonic adaptation functions were obtained: As the adaptor moved away from the category boundary, there was an initial increase in adaptation, followed by a subsequent decrease. On the assumption that selective adaptation taps a prephonetic, auditory level of processing, these findings permit the following conclusions. First, at an auditory level there is a limit on the range of stimuli along a continuum that is treated as relevant to a given contrast; that is, the stimuli along a continuum are effectively grouped into auditory categories. Second, stimuli within an auditory category vary in their effectiveness as category members, providing an internal structure to the categories. Finally, this internal category structure at the auditory level, revealed by the adaptation procedure, may provide a basis for differences in perceived category goodness at the phonetic level.
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43.70.Dn Disordered speech
43.70.Fq Acoustical correlates of phonetic segments and suprasegmental properties: stress, timing, and intonation

Physical characteristics of the lips underlying vowel lipreading performance

Allen A. Montgomery and Pamela L. Jackson

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2134-2144 (1983); (11 pages) | Cited 4 times

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To evaluate the relationship between physical characteristics of the lips during vowel production and vowel lipreading confusions, four female talkers were videotaped producing 15 American English vowels and diphthongs in an /h/‐V‐/g/ context. Ten normal‐hearing adults identified the stimuli through lipreading. Three analyses were performed. First, using confusion matrices for individual and pooled talkers, the stimuli were located in a two‐dimensional space using multidimensional scaling. The ten monophthongs revealed a clear lip spreading/rounding dimension and a tongue height dimension, and while diphthongs also showed influence of lip rounding, more variability on the tongue height dimension was apparent. Second, tracings were made of the talkers’ lips on a single videotape field representing the maximum opening or constriction for each of the 40 monophthong tokens (ten vowels×four talkers), and six physical measurements of the tokens were derived as descriptors of the vowel nuclei. Third, difference scores and other measures of physical pairwise similarity were used as predictors of two ways of representing the vowel lipreading confusions in a multiple regression paradigm. Results indicated that the physical measures were moderately successful as predictors of vowel perception (accounting for approximately 50% of the variance in the perceptual distance measure), although considerable differences in the strength of the prediction occurred among talkers.
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43.70.Dn Disordered speech
43.72.Ar Speech analysis and analysis techniques; parametric representation of speech

Children’s perception of speech in reverberation

Arlene C. Neuman and Irving Hochberg

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2145-2149 (1983); (5 pages) | Cited 7 times

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Recordings of nonsense syllables (VCV construction) were presented to groups of children aged 5, 7, 9, 11, and 13 years and young adults under monaural (reverberation time=0.6 s) and binaural (reverberation times=0, 0.4, and 0.6 s) conditions of reverberation. Phoneme identification performance was affected by age, reverberation, and mode of presentation (monaural versus binaural). The major findings were (1) phoneme identification scores in reverberant conditions improved with increasing age and decreased with increased reverberation time; (2) children’s performance in reverberant conditions did not reach asymptote until age 13; (3) binaural performance was consistently better than monaural performance for all age groups, with 5‐year‐olds showing the largest binaural advantage.
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43.70.Dn Disordered speech
43.55.Br Room acoustics: theory and experiment; reverberation, normal modes, diffusion, transient and steady-state response
43.50.Qp Effects of noise on man and society

The role of spectral cues in discrimination of voice onset time differences

Sigfrid D. Soli

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2150-2165 (1983); (16 pages) | Cited 4 times

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The influence of spectral cues on discrimination peaks in the region of the phonetic voicing boundary was examined. The discriminability of voice onset time (VOT) differences of the same temporal magnitude was assessed using stimuli from labial and velar consonant–vowel VOT continua that differed in the timing of spectral changes associated with the first formant (F1) transition, and in the location of the phonetic boundary. Subjects were initially given labeling tests and fixed‐standard AX and all‐step discrimination tests on both series. Half the subjects then received all‐step discrimination training on one series and half received training on the other series. Finally, all subjects were again given the labeling and discrimination tests on both series. Just noticeable differences (jnds) in VOT were estimated from the all‐step functions before and after training. Initial jnds showed that VOT discrimination was most accurate around the voicing boundary on the two continua, where differences in F1 onset frequency accompany variations in VOT. jnds on both series decreased significantly after training, although these regions of greater sensitivity remained. No evidence was seen of increased sensitivity around ±20‐ms VOT, as expected if auditory processing constraints were influencing temporal order judgments. Comparisons of post‐training jnds within and across series indicated that spectral components of VOT, primarily F1 onset frequency differences, exert a substantial influence on discrimination, and, along with other spectral cues provided by source differences at stimulus onset, can account for the discontinuities in discrimination often reported in research with VOT continua. Large phonetic effects also were seen in the initial performance of all subjects: jnds decreased consistently as standards drew nearer the voicing boundary. However, these effects were absent in the final jnds for most subjects. Implications of these findings for the understanding of basic auditory and attentional processes in speech perception are discussed.
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43.70.Dn Disordered speech
43.66.Fe Discrimination: intensity and frequency
43.70.Fq Acoustical correlates of phonetic segments and suprasegmental properties: stress, timing, and intonation

The effect of a hearing aid on the speech‐reception threshold of hearing‐impaired listeners in quiet and in noise

A. J. Duquesnoy and R. Plomp

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2166-2173 (1983); (8 pages) | Cited 5 times

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The monaural free‐field speech‐reception threshold (SRT) without and with a hearing aid was investigated for conversational sentences presented to 50 hearing‐impaired listeners. SRT without a hearing aid was measured in quiet and in noise at levels of 40, 55, 70, and 85 dBA. SRT with a hearing aid was obtained in quiet and at noise levels of 25, 40, 55, and 70 dBA. The noise had a long‐term average spectrum equal to that of the sentences. The 50 subjects were equally distributed over five degrees of pure‐tone hearing loss and five types of hearing impairment (sensorineural high‐frequency losses, with or without recruitment; flat audiogram of a sensorineural, mixed, or conductive origin). It is shown that a model of SRT as a function of noise level, developed by Plomp [J. Acoust. Soc. Am. 63, 533–549 (1978)] gives a good description of the SRT values measured, both without and with a hearing aid. The data illustrate that, generally, current hearing aids do not improve speech intelligibility in noise beyond, roughly, 60 dBA.
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43.71.Gv Measures of speech perception (intelligibility and quality)
43.66.Ts Auditory prostheses, hearing aids
43.66.Sr Deafness, audiometry, aging effects

Harmonics of S motion on bowed strings

Bo Lawergren

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2174-2179 (1983); (6 pages)

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Lossless bowed strings have usually been thought to possess a motion discovered by Helmholtz in 1863. However, it was shown [Acustica 44, 194–206 (1980)] by the author that a more complicated standing wave motion, the S motion, exists on such strings provided both the bowing distance and bowing force are above certain minimum values. This paper explores S‐motion harmonics which give arise to waveforms of considerable complexity on very thin strings. Equations are found which describe the experimentally determined waveforms as a function of bow position, bow velocity, and observation point. In the special case of square velocity waves at the bow point, the equations give quantized values for the bow/string sticking duration. That result agrees with Raman’s [Proc. Ind. Assoc. Adv. Sci. 15, 1–158 (1918)] prediction. In general, however, the waveforms have rounded corners.
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43.75.De Bowed stringed instruments

Acoustic ground impedance meter

Allan J. Zuckerwar

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2180-2186 (1983); (7 pages) | Cited 2 times

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A compact, portable instrument has been developed to measure the acoustic impedance of the ground, or other surfaces, by direct pressure‐volume velocity measurement. A Helmholtz resonator, constructed of heavy‐walled stainless steel but open at the bottom, is positioned over the surface having the unknown impedance. The sound source, a cam‐driven piston of known stroke and thus known volume velocity, is located in the neck of the resonator. The cam speed is variable up to a maximum 3600 rpm, and since the cam has five lobes, the maximum acoustic frequency is 300 Hz. The sound pressure at the test surface is measured by means of a microphone flush mounted in the wall of the chamber. An optical monitor of the piston displacement permits measurement of the phase angle between the volume velocity and the sound pressure, from which the real and imaginary parts of the impedance can be evaluated. The prototype instrument can measure specific ground impedance at normal incidence up to 50 times the specific impedance of air. Detailed design criteria and results of measurements on an uncultivated grass field are presented.
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43.58.Bh Acoustic impedance measurement
43.50.Vt Topographical and meteorological factors in noise propagation
43.50.Lj Transportation noise sources: air, road, rail, and marine vehicles

Ground couplings and measurement frequency ranges of vibration transducers

Sadao Omata

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2187-2192 (1983); (6 pages)

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Vibration transducers do not faithfully follow the ground motion at high frequencies, since a resonant system is formed by the weight of the vibration transducer and the contact compliance of a placing point. Particularly, the contact resonances cause errors in measurement and place restrictions on the measurement frequency range. The characteristics of the effect of ground coupling depend on the type and condition of the ground surface and the method of planting the transducer. This paper examines the characteristics of the frequency response of the vibration transducer placed on the ground and provides the optimum relationships between the base area and the weight of the transducer for decreasing the effect of ground coupling under all conditions. The relationships are represented in the figures for the user’s convenience. When the vibration transducers designed to satisfy the relationship proposed here are employed for the measurement of the ground vibration, it is shown that the errors in measurement caused by the ground coupling decrease considerably. As compared with the old vibration transducers the measurement frequency ranges are markedly spread out.
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43.38.Ar Transducing principles, materials, and structures: general
43.40.At Experimental and theoretical studies of vibrating systems
43.40.Yq Instrumentation and techniques for tests and measurement relating to shock and vibration, including vibration pickups, indicators, and generators, mechanical impedance

Log‐periodic acoustic lens–acoustic filter plate study. II

Robert L. Sternberg, Warren A. Anderson, Owen P. Dickson, Howard F. Ilson, and Peter S. Marchese

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2193-2199 (1983); (7 pages)

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Graphical experimental data in the form of passive receiving scanning beam patterns is presented for several high resolution acoustic lens–acoustic filter plate combinations. They show the comparative properties of various types of flat and curved filter plates when used in such acoustic antennas. Experimental data relating the achieved frequency‐independent constant beamwidth of the several lens–filter plate combinations to the governing parameters of the filter plates are summarized for empirical design purposes. The basic experiments reported were conducted over the frequency range from 25 to 1000 kHz but the results can be scaled to any frequency range of the corresponding scaled width. As a receiving antenna, the acoustic lens–acoustic filter plate device eliminates the distortion imposed on the spectral content of a received multifrequency signal as a function of angle‐off‐boresight which is inherent in the use of conventional variable beamwidth directional receiving antennas.
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43.38.Ar Transducing principles, materials, and structures: general
43.58.+z Acoustical measurements and instrumentation
43.30.Cq Ray propagation of sound in water
43.58.Kr Spectrum and frequency analyzers and filters; acoustical and electrical oscillographs; photoacoustic spectrometers; acoustical delay lines and resonators
43.60.Gk Space-time signal processing, other than matched field processing

Experimental constant beamwidth transducer

A. L. Van Buren, L. Dwight Luker, M. D. Jevnager, and A. C. Tims

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2200-2209 (1983); (10 pages)

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The theory of a broadband constant beamwidth transducer (CBT) which is based on Legendre function shading of a spherical cap was described in a previous report [P. H. Rogers and A. L. Van Buren, J. Acoust. Soc. Am. 64, 38–43 (1978)]. Theoretical calculations showed the CBT to have uniform acoustic loading, extremely low side lobes, virtually no nearfield, an essentially constant beam pattern for all frequencies above a certain cutoff frequency, and a flat transmitting current response over a broadband for piezoelectric drive. In this paper we present experimental results obtained for a prototype CBT based on fifth‐order Legendre function shading. The transducer is a spherical cap with a diameter of 30.5 cm and a total cap angle of 50°. Measurements on the CBT showed it to possess very low side lobes and a nearly constant beamwidth over the frequency range from 20 to 140 kHz for ambient pressures up to 3.4 MPa. We also present formulas useful in the design of a CBT which is to be used as a transmitter and/or receiver. The formulas involve simple algebraic and trigonometric expressions which can be readily evaluated using a pocket calculator.
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43.38.Ar Transducing principles, materials, and structures: general
43.30.Yj Transducers and transducer arrays for underwater sound; transducer calibration
43.30.Jx Radiation from objects vibrating under water, acoustic and mechanical impedance
43.20.Px Transient radiation and scattering

Effect of mounting constraints on the response of piezoelectric disks

D. B. Bogy and R. T‐K. Su

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2210-2215 (1983); (6 pages)

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An experimental investigation was conducted to determine the effects of different edge conditions and face mount backing conditions on the electrical response of strongly coupled piezoelectric disks with electroded faces on which spatially nonuniform forces are applied by a pencil lead breaking mechanism. Various mounting schemes were employed to simulate traction‐free, simply supported, and fixed edge conditions. The response was found to be relatively insensitive to changes in the edge conditions. Experiments were also conducted on a commercially available transducer in various stages of dismantlement. It was revealed that the main structural element for controlling the electrical output was the impedance matched backing that is epoxied to the inner face of the crystal. It was concluded that mathematical models for characterizing transducers subject to nonuniform face loadings can incorporate the analytically most convenient edge conditions but must also include a suitable model for the backing.
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43.38.Fx Piezoelectric and ferroelectric transducers
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
43.38.Ar Transducing principles, materials, and structures: general

Bottom reverberation in the oceans

Kenneth V. Mackenzie

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2216-2216 (1983); (1 page) | Cited 1 time

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The location of reverberation measurements have been declassified and are now identified.
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43.30.Gv Backscattering, echoes, and reverberation in water due to combinations of boundaries
43.30.Bp Normal mode propagation of sound in water
92.10.Vz Underwater sound

A laser study of multiple reflections within parallel noise barriers

D. A. Hutchins and D. Pitcarn

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2216-2218 (1983); (3 pages)

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A laser has been used to determine acoustic wave paths from a source, located between parallel noise barriers, to the top of each barrier. Various barrier designs have been studied, and conclusions drawn on the likely effect of parallel siting on sound levels at a protected receiver for a typical traffic noise geometry.
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43.50.Lj Transportation noise sources: air, road, rail, and marine vehicles
43.50.Yw Instrumentation and techniques for noise measurement and analysis
43.50.Gf Noise control at source: redesign, application of absorptive materials and reactive elements, mufflers, noise silencers, noise barriers, and attenuators, etc.

Incurrence and alterations in contralateral tinnitus following monaural exposure to a pure tone

I. M. Young and L. D. Lowry

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2219-2221 (1983); (3 pages)

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A subject who had a tinnitus with 10 000‐Hz pitch equivalent in the left ear and no tinnitus in the right ear was exposed in the left ear to a steady tone of 2000 Hz, 107 dB SPL, for 10 min. This exposure resulted in a permanent tinnitus in both ears with similar pitch of approximately 10 000 Hz and loudness of 50–55 SPL (5–10 dB SL). When the left ear of this subject was exposed to a steady 500‐Hz pure tone at 121 dB SPL for 21 min, tinnitus disappeared temporarily from the stimulated ear but was heard in the nonstimulated ear. In the left ear: 3 h after stimulation, tinnitus reappeared as a mixture of multiple pitches superimposed upon broadband noise and/or low‐pass filtered noise; 24 h after stimulation, tinnitus pitch changed to 3260 Hz, two days later to 5100 Hz, three days later to 8310 Hz and one week later to the original 10 000 Hz and has remained there since. In the nonstimulated right ear: Immediately after cessation of stimulation, tinnitus pitch was 6700–8000 Hz for 48 h; thereafter, tinnitus has been fluctuating between 8000–9000‐Hz tone and a narrow‐band noise centered around 7986 Hz with a bandwidth of 2710 Hz; the tinnitus did not return to the previous pre‐exposure pitch of 10 000 Hz until about four weeks after exposure. We suggest that these contralateral effects of tinnitus are mediated by the central auditory system.
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43.66.Ki Subjective tones
43.66.Ba Models and theories of auditory processes
43.66.Lj Perceptual effects of sound

Advantage of speaker as listener in a vowel identification task

Arlene Earley Carney, Thomas Edman, Winifred Strange, and James J. Jenkins

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2222-2223 (1983); (2 pages)

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Six talkers (two men, two women, and two children) listened to recordings of their own vowels, and to vowels produced by five other speakers both in isolation and pVp contexts. On the whole, subjects perceived their own vowel productions more accurately than those of the other speakers. Further, they perceived vowel tokens in a pVp context more accurately than in isolation even when they were presented with their own vowel tokens. Thus both speaker normalization and formant‐transition information can be considered important variables in determining vowel identification.
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43.70.Dn Disordered speech

Erratum: ‘‘Resonant porous material absorbers’’ [J. Acoust. Soc. Am. 72, 1989–1999 (1982)]

James A. Moore and Richard H. Lyon

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2224-2224 (1983); (1 page)

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Abstract Unavailable
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43.20.Hq Velocity and attenuation of acoustic waves
43.20.Mv Waveguides, wave propagation in tubes and ducts
43.55.Ev Sound absorption properties of materials: theory and measurement of sound absorption coefficients; acoustic impedance and admittance
99.10.Cd Errata

Erratum: ‘‘Visual and tactual perception of syllable number in sentence stimuli’’[J. Acoust. Soc. Am. 73, 367–371(1983)]

Michelle S. Bourgeois and Howard Goldstein

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2224-2224 (1983); (1 page)

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Abstract Unavailable
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43.70.Dn Disordered speech
43.66.Wv Vibration and tactile senses
43.66.Sr Deafness, audiometry, aging effects
99.10.Cd Errata

Scaling of handbells

H. John Sathoff and Thomas D. Rossing

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2225-2226 (1983); (2 pages)

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Abstract Unavailable
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43.75.Kk Bells, gongs, cymbals, mallet percussion, and similar instruments

Human sensitivity to low‐frequency sound

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2227-2227 (1983); (1 page)

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Abstract Unavailable
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43.50.Qp Effects of noise on man and society

Equation for combustion noise

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2227-2227 (1983); (1 page)

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Abstract Unavailable
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43.50.Ed Noise generation

Low‐noise bandpass amplifier

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2227-2228 (1983); (2 pages)

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Abstract Unavailable
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43.50.Yw Instrumentation and techniques for noise measurement and analysis
43.38.Lc Amplifiers, attenuators, and audio controls

Structural analysis of shells: a computer program

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2228-2228 (1983); (1 page)

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Abstract Unavailable
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43.40.Ey Vibrations of shells
43.58.Ta Computers and computer programs in acoustics

Nonlinear Scattering of Ultrasound by Bubbles: Numerical and Experimental Investigations with Application to their Detection

Brian C. Eatock

J. Acoust. Soc. Am. Volume 73, Issue 6, pp. 2228-2228 (1983); (1 page)

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Abstract Unavailable
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43.25.Yw Nonlinear acoustics of bubbly liquids
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