bluuebunny/crossref_metadata_2025 huggingface dataset:
Short duration adaptation effects upon lateralization
Authors: Elliott Donald N. , Geula Changiz
Published: October 2005

Changes in interaural phase relations or intensity differences required to return a binaural intercranial image to the median plane following adaptation of one ear have been determined for three Os. The monaural adapting signal was 500 Hz at 60 dB SL, and of 150-, 300-, or 1000-ms duration. The 300-ms binaural signal input to be judged for location was also 500 Hz, and was varied either in interaural phase or intensity in order to produce a median plane lateralization (MPL). This binaural signal followed the offset of the adapting signal by 0, 30, 1000, 2000, 5000, or 10 000 ms. It was found that sizable interaural phase or intensity differences are required to produce a median plane image following adaptation. The effect develops very rapidly and lasts for an extended period—for some Os being evident 10 s after a 150-ms adapting signal. Time/intensity ratios required for MPL were found to increase with increasing adaptation effects. Sizable asymmetries were found for some Os, with far larger effects evident after adapting one ear than the other.
Vertical sound localization in monkeys
Authors: Brown Charles H.
Published: October 2005

Minimum audible angles for vertical localization were psycho-physically determined in Old World monkeys (Macaca). Monkeys were trained through positive reinforcement operant conditioning procedures to contact a response disk (observing response) initiating a repetitive series of brief pulses (approximately 300 ms) presented from a standard location directly in front of the monkey at 0° elevation. At random intervals the stimulus changed location from the standard to one of four comparison locations. The monkeys reported the change in elevation by releasing the response disk. The minimum audible angle for vertical localization was assessed through the method of constant stimuli under free-field conditions in an anechoic chamber. The test stimuli consisted of primate vocalizations and bands of noise adjusted in bandwidth. Minimum audible angles ranged from approximately 3° to 20° for signals of various bandwidths. Monkeys were unable to detect changes in elevation for signals with upper cutoff values (of the spectrum) below 2000 Hz. The results suggest that minimum audible angles for vertical localization were dependent upon torso reflections rather than pinna transformations. [Work supported by NSF.]
Differentiation of plain and pharyngal fricatives in Lybian Arabic
Authors: Krieg Laurence J. , Benson Peter J. , Catford J. C.
Published: October 2005

The considerable inventory of contrasting Arabic fricatives presents some hitherto unanswered questions to phonetic investigators: the acoustic cues differentiating the contrasts have only been partially specified [e.g., al-Ani, Arabic Phonology (The Hague, 1970)]; it has not been satisfactorily demonstrated whether fricative noise itself or only the surrounding vowels differentiate between corresponding pairs of pharyngalized (“emphatic”) and nonpharyngalized fricatives [e.g., Jakobson, ‘“Mufaxxama” …,’ Selected Writings 1, 510–522 (1962)], Bonnot [“Recherche experimentale sur la nature des consonnes emphatiques de l'arabe classique,” Trav. Inst. Phonet. Strasbourg 9, 47–88 (1977)]. A dialect of Lybian Arabic which contrasts an unusually large number of plain versus pharyngalized fricatives is recorded; measurement is made of time-domain variables such as VOT, rise time, and relative amplitude of the fricative. Spectral information is averaged together to provide representative spectra of each of the contrastive fricatives. These spectra are then transformed using various weighting functions; the original, the transformed spectra and time-domain measurements are then compared and grouped by multivariate analysis techniques to provide evidence for the general phonological grouping of fricatives in this dialect and the role of pharyngalized/plain contrast.
Evaluation of the sensitivity of the speech perception in noise test to the linguistic and acoustic cues utilized in speech discrimination
Authors: Owen J. H.
Published: October 2005

The Speech Perception in Noise (SPIN) test [D. Kalikow, K. Stevens, and L. Elliott, J. Acoust. Soc. Am. 61, 1337–1351 (1977)] is a sentence test which measures the contribution of linguistic cues to the discrimination score. This measure is known as the difference score. This study was conducted to determine if language skills are related to this score. Ninety subjects, ranging in age from 8 to 11 yr and from 18 to 79 yr, were divided equally into three groups: normal hearing/normal language, impaired hearing/normal language, impaired hearing/impaired language. Subjects were administered the SPIN (at 6 SNRs), language, and IQ tests. Results indicate that the difference score is not significantly related to linguistic skills, age, or IQ, but is related to hearing loss and SNR. Interpretation of results indicates, however, that the difference score is influenced by test sentence audibility.
Dichotic identification of complex sounds
Authors: Lauter Judith L.
Published: October 2005

Ear advantages for sets of speech and nonspeech sounds were measured with four listeners. The speech sounds were: edited fragments of real stop CV syllables, synthetic versions of the full syllables, and six natural vowels. Nine sets of nonspeech sounds were tested; sets differed according to temporal variations in frequency, intensity, duration, and bandwidth. Task was always 6AFC, with a nonverbal response. Results bear on three issues: (1) methodology, (2) expression of results, and (3) the possible acoustical basis for ear advantages. (1) If appropriate methods are used and individual scores retained, ear advantages that are both large (40% difference between ears) and reliable over time can be obtained. (2) The categories of “left, right, and zero” are not sufficient to describe dichotic data; a continuum of ear advantage (25% REA is “more right” than 10% REA) is suggested, which allows comparisons of one listener's performance on several sounds, and comparisons among listeners. (3) Ear advantages seem to reflect the acoustical characteristics of test sounds. For example, right-most ear advantages are observed for multidimensional sounds, or for sounds that include either short-duration elements or changes in bandwidth over time. [Work supported by NINCDS Grant NS03856.]
Perceptual assessment of fricative-stop coarticulation
Authors: Repp Bruno H. , Mann Virginia A.
Published: October 2005

The perceptual dependence of stop consonants on preceding fricatives [V. A. Mann and B. H. Repp, J. Acoust. Soc. Am. Suppl. 1 64, S17 (1978)] was further investigated in a series of experiments employing fricative noises and CV portions excerpted from natural utterances ([∫ta], [∫ka], [sta], [ska]), both in isolation and in combination with synthetic stimulus portions drawn from a [∫]-[s] or [ta]-[ka] continuum. These experiments consistently replicated our original finding that listeners report more velar stops following [s]. In addition, we found that natural fricative noises contain cues to the following stop consonants, as revealed in subjects' responses to isolated natural fricative noises and to combinations of these noises with synthetic CV portions. Most importantly, we found that the formant transitions in natural CV portions vary with the preceding fricative in perceptually significant ways: Subjects' responses to excised natural CV portions (with bursts and aspiration removed) were biased towards a relatively more forward place of stop articulation when the CVs had originally been preceded by [s], and this held both for CV portions presented in isolation and when combined with synthetic fricative noises. Thus an articulatory explanation for the effect of preceding fricatives on stop consonant perception is supported.[Work supported by NICHD and BRS.]
Phoneme confusions as a function of age
Authors: Piper Neil , Gelfand Stanley A. , Hochberg Irving , Silman Shlomo
Published: October 2005

Initial and final consonant confusions in a variety of vowel environments were studied as a function of age from 20–69 years in decades using the CUNY Nonsense Syllable Test [Resnick, S. B. et al., Asha 18, 651, (1976)]. In terms of number of errors, the effects of age, level, and subset were significant. More errors were made by the elderly. Results obtained at MCL and MCL + 8 dB were not significantly different; and these were significantly better than at MCL − 8 dB. Subset differences revealed that vowel environment affected final unvoiced consonant recognition in a systematic manner: Fewest errors were associated with /u/ and the greatest number with /i/; errors associated with /a/ falling between these. This was true for young and old alike. Combined error matrices revealed that confusions made by young listeners were essentially between acoustically similar phonemes and tended to cluster (/θ ↔ f/, /δ ↔ v/). Interestingly, the direction of confusion tended to be vowel dependent. For the elderly, confusions were far more diffuse with far less tendency toward clustering among particular phonemes. The implications are discussed. [Work supported by VA.]
Psychoacoustic model of categorical perception for speech and nonspeech continua: A stringent test
Authors: Espinoza-Varas Blas
Published: October 2005

At the 98th ASA meeting we proposed that discrimination between two stimulus values, xp, xr, of a continuum that is perceived categorically is based on the physical parameter Φ, where Φ = |xp − xr|/|xr − xB|;xB is the category boundary; xp is the member of the stimulus pair proximal to xB; and xr the one remote to xB [Espinoza-Varas, J. Acoust. Soc. Am. Suppl. 1 66, S49(A) (1979)]. Since in this model discriminability is a function of Φ, and Φ a function of xB, it follows that shifts in the value of xB should produce changes in the values of Φ that are correlated with the changes in discriminability. In this paper we examined this more stringent prediction by measuring the correlation between changes in discriminability and in Φ induced by shifting the boundary xB through selective adaptation to an endpoint stimulus of the continuum. The continua studied were VOT [Eimas et al, Cognitive Psychology 4, 99–109 (1973)], duration of formant transition [Cooper et al., J. Exp. Psychol.: Human Perception and Performance, 2, 92–104 (1976)], and musical intervals [Zatorre et al., Percept. Psychophys. 26, 384–395 (1979)], and the Pearson correlations obtained were 0.90, 0.74, and 0.63, respectively. These results further support the claim that Φ is a physical parameter on which discrimination is based in categorically perceived continua; and that enhanced discriminability at the boundary is a consequence of the listener adopting such boundary rather than vice versa. [Supported by NRC Postdoctoral Fellowship to the author.]
Central and monaural factors in the summation of F2 and F3 transition onsets
Authors: Schwab Eileen C. , Sawusch James R.
Published: October 2005

Previous research has indicated that F2 and F3 transition onsets of velar consonants may summate to simulate a “burst-like” feature. This F2-F3 summation may explain why subjects make more stop responses to a velar stop-semivowel series than to a bilabial series. When the onset amplitude of F2 and F3 is reduced for these stimuli, there is no significant difference in the number of stop responses made to the velar and bilabial consonants. Similarly, when the third formant is eliminated entirely, the number of velar stop responses is reduced. Thus, there is evidence for the perceptual integration of velar F2 and F3 transition onsets. The current research was designed to determine whether the locus of perceptual summation is central (binaural) or monaural. Subjects identified dichotically presented bilabial and velar stop consonants and semivowels. An isolated formant was presented to one ear and the remaining two formants were simultaneously presented to the other ear. Monaural perceptual integration predicts that there should be no difference in the stop-semivowel boundary location for velars and bilabials when F2 and F3 are presented to different ears. [Work supported by NSF and NIMH.]
Processing of acoustic signals by cerebellar neurones of the big brown bats, Eptesicus fuscus
Authors: Jen P. H. S. , Schlegel P.
Published: October 2005

The cerebellum of a vertebrate not only receives signals from the motor areas of the cerebral cortex but also receives different impulses indirectly from almost all sensory receptors. With Eptesicus fuscus, we studied the response properties of cerebellar neurones to acoustic stimuli (40 ms duration, 0.5 ms rise-decay time). Single neurones responding to auditory stimuli could be isolated from rather large areas of the bat's cerebellar vermis and hemispheres. They were usually spontaneously inactive and discharged either tonically or phasically. These units had latencies between 4 and 13 ms and best frequencies between 22 and 77 kHz. The Q10-dB values of their triangular tuning curves were between 1.4 and 16.6 with the majority below 10. Minimum thresholds were between 12 and 65 dB SPL. When acoustic stimuli were delivered through the earphones, tuning curves measured from each ear alone were nearly identical in shape and best frequency. At present, we do not know whether the units we studied were exclusively auditory or multimodal neurones [Work supported by DFG of West Germany and NSF of USA.]
Comparison of forward masking and simultaneous masking tuning curves in the monkey
Authors: Serafin John V. , Moody David B. , Stebbins William C.
Published: October 2005

Psychophysical tuning curves were obtained from Old World monkeys via a positive reinforcement operant procedure. These tuning curves were found in two different manners. In the first, simultaneous tone-on-tone masking was utilized, while the second procedure involved a forward masking paradigm. In this condition, the subjects' task was to detect brief (30 ms) tone pulses which followed each of a train of masking pulses. With both paradigms, threshold masker levels were determined by a tracking procedure. In comparing the two types of curves, it was found that the forward masking tuning curves were generally more sharply tuned than were the simultaneous masking tuning curves at a given frequency. This fact was verified by computing Q10 values for the individual curves, as well as by a comparison of the slopes of the tuning curves under the two masking conditions.
The effect of intensity upon the ability of the binaural auditory system to process information presented at rapid rates
Authors: Dye Raymond H.
Published: October 2005

Previous research has shown that threshold values of interaural differences of time (IDT) increase as the number of clicks in a click train is decreased and as the time between the clicks (inter-click interval) is decreased [Hafter and Dye, J. Acoust. Soc. Am. Suppl. 1 64, S35 (1978)]. This decline in efficiency has been modeled by an exponential decay, N = nk, where N is the number of neural responses, n is the number of clicks, and k ⩽ 1.0 and k = f(ICI). The present study sought to determine the effects of intensity upon the decline in efficiency by measuring threshold values of IDT as a function of the inter-click interval (5, 2, and 1 ms) and number of clicks (1, 2, 4, 8, 16, 32) for click levels of 20, 40, 60, and 80 dB SPL. The results show that increased level causes the threshold vs n functions to be shifted downward for ICIs long enough to allow near perfect integration of information (5 ms), but causes both a downward shift and an increase in slope (larger k) when the ICIs are shorter.
Study of the formant detection thresholds
Authors: Lublinskaia V. , Escudier P. , Carré R.
Published: October 2005

The detection thresholds of the first and second formants have been studied in various conditions using synthetic vowels. The test signals consisted of 30 harmonic components with F0 = 100 Hz. The spectrum envelope was modulated in order to get two peaks (F1 and F2) with slopes computed in dB/Bark. The signals were calculated in real time, the formant amplitude being controlled by the experimenter in an anechoic room. Results obtained show the importance of the distance between the two formants and the importance of the slopes. Test signals have also been used as input signals of our model of the cochlea [J. M. Dolmazon and L. Bastet, J. Acoust. Soc. Am. Suppl. 1 65, S14 (1979)] in order to facilitate the interpretation of the data and to study the correctness of the model. Results are discussed.
Preliminary psychophysical results of electrically stimulating the auditory nerve in man
Authors: Shannon Robert V. , Owens Elmer , Kessler Dorcas
Published: October 2005

A series of psychophysical tests and speech tests were performed on a patient implanted with a cochlear prosthesis. The device was a multi-electrode scala tympani insert connected to a percutaneous plug. Threshold data and growth of loudness data will be presented for sinusoidal and pulsatile waveforms and several electrical configurations, i.e., monopolar referenced to an external ground or bipolar pairs of electrodes. The dynamic range for electrical stimulation was about 15 dB, composed of two segments. From threshold to about 10 dB above threshold loudness grows very slowly. In the next 5 dB the loudness grows from very soft to uncomfortably loud. This growth is the same for sinusoidal and pulsatile stimuli, and for apical or basal cochlear stimulation. Pitch rankings were obtained for different electrodes and were consistent with the ranking expected on the basis of cochlear position. Speech reception tests run with single channel stimulation of the multi-electrode array showed 40% reception of sentence material and 50% reception of open-set spondee words without lip-reading cues. [Work supported by grants NS 11804, NS 72367, and NS12998.]
Auditory Mach bands
Authors: Wilkes M. R. , Soderquist D. R.
Published: October 2005

Comparison stimuli, incremented in 20-Hz intervals in the frequency range of 660 to 1400 Hz, were matched in loudness to a standard stimulus of 600 Hz. All comparisons were performed in the presence of a bandlimited noise pattern having an increase in intensity between 880 and 1200 Hz. No suppression effects analogous to auditory Mach bands were obtained using this direct masking technique. The comparison stimuli and noise pattern were then presented in a forward masking paradigm and suppression effects were obtained at the intensity flections in the noise pattern. The results of both experiments closely agree with earlier results. [T. Houtgast. J. Acoust. Soc. Am. 51, 1885–1894 (1972)].
Random vibration of an impacting oscillator; the distribution of peaks
Authors: Davies Huw G.
Published: October 2005

Random vibration of a two-degree-of-freedom oscillator with mass impacting springlike stops is discussed. The excitation is stationary Gaussian white noise. The mean-square acceleration of the impacting mass remains finite. An exact expression is obtained for the joint probability density function of displacement, velocity, and acceleration of the impacting mass. The pdf of positive peaks is obtained, at least to within a constant, which must be determined numerically. Increasing concentrations of peaks occur as the strength of the stops is increased. The exact peak pdf is compared with an approximate expression obtained by assuming that the response is a narrow-band process. The comparison covers a wide range of values of the ratio of expected frequency of peaks to expected frequency of zero up-crossings. Marked differences between the exact and approximate expressions are obtained when the frequency ratio even slightly exceedes unity.
On the nonlinear response of a submerged cylindrical shell to transient acoustic loading
Authors: Giltrud M. E.
Published: October 2005

This work gives the nonlinear solution for the response of isotropic cylindrical shells to transient acoustic loading. The approach is numerical and in particular applies the USA-STAGS code which combines the finite element method for the structure with the Doubly Asymptotic Approximation (DAA) for the fluid. We assess the influence of both large strain and plasticity on the response of the structure and the fluid. One important finding is that the modal responses are dependent upon the loading intensity, a situation not observed for the linear case.
Orthogonal coding of linear prediction log area ratios
Authors: Zahorian Stephen A.
Published: October 2005

In this experimental study, the principal-components statistical analysis procedure was used to obtain an uncorrelated orthogonal parameter set derived from a linear transformation of LPC log area ratios. The log area ratios of continuous speech for several adult male and female speakers were computed using an autocorrelation linear predictive vocoder analyzer. Group-averaged principal-components basis vectors, the coefficients for the linear transformations of the log area ratios, were calculated for the male and female speaker groups. Speech was synthesized with a residual-excited LP vocoder using LP coefficients derived from a small number of group-averaged log area ratio principal-components factors. A sentence preference experiment was conducted in order to compare speech synthesized from LP log area ratio principal components versus speech synthesized from spectral band energy principal components and speech synthesized from a standard LP vocoder. The results of the sentence preference experiment indicate that the orthogonal LP log area ratio parameters are inferior to both spectral band-energy orthogonal parameters and to the original LP coefficients, in terms of the information retained for a given number of parameters. The apparent discrepancy in the findings of the present study versus the results of an earlier experiment [M. R. Sambur, “An Efficient Linear Prediction Vocoder,” Bell Syst. Tech. J. 54, 1693–1723 (1975)] is probably due to the analysis techniques of the previous experiment (analysis applied separately for each sentence and each speaker) as compared to the more general analysis conditions of the present study (one set of basis vectors used to characterize a long speech passage for several speakers).
Subjective speech-to-noise-ratio as a single absolute performance measure for digital waveform coders
Authors: Nakatsui Mamoru
Published: October 2005

The ultimate performance measure for evaluating a voice communication system is the subjective quality of the received speech. To this end we tested subjective speech-to-noise-ratio (SNRsubj) as an absolute measure of overall speech quality for digital waveform coders. High quality digital recordings of two sentences by each of two speakers were processed by nine different waveform coder and transmission rate combinations, and then paired with reference signals corrupted by varying amount of multiplicative white noise. The SNRsubj of a coded test signal is defined as the amount of multiplicative white noise introduced into the uncoded original signal so that it is judged equally preferable to the coded signal. A total of 392 pairs were randomized and presented to 11 naive listeners for preference testing. The SNRsubj for the nine coder configurations varied from 14 to 40 dB and was found suitable to represent overall speech quality of waveform coders in a single dimension. None of two main experimental factors, speech sample and listener, introduced any statistically significant variation in the SNRsubj estimate. The relationship between the SNRsubj and several objective measures are also discussed.
A design study for “spell mode” in a text-to-speech system
Authors: Goldhor Richard , Bernstein Jared
Published: October 2005

No matter how excellent the quality of synthetic speech in a text-to-speech system, in some circumstances a listener will not understand what has been said. In such cases it would be useful to put the system into a spell mode and have it spell out a portion of text. This paper reports a study of how human speakers spell out loud and presents an algorithm for assigning prosodic content to letter strings that comprise words. Four speakers spelled out loud from a list of words that includes items of varying length and degree of phonological, morphological, and orthographic complexity. In the belief that human-like spelling prosody facilitates word recognition by listeners, tape recordings were analyzed to identify common types of letter group formation as signaled by fundamental frequency, duration, pauses, and glottal stops. We will present an algorithm that generates spelling prosody on the basis of orthographic form and length, syllabication, and morphology. Finally, we will play a tape recording of spellings synlhesized with this algorithm.
An historical perspective of noise control
Authors: Warnaka Glenn E.
Published: October 2005

Annoyance due to noise or noise pollution is, perhaps, the oldest recognized form of pollution. Although the ancients (Egyptians, Greeks, and Romans) had a surprising knowledge of acoustics and a recognition of industrial and urban noise, there appears to have been little application of technology to the problem. In more modern times, the power of noise as an annoyance has been intuitively understood and fancifully exploited in writing and the motion pictures. In the same era, the military noise problem has been recognized, and considerable technological effort has been expended to reduce noise and exploit its generation under battle conditions. Community noise limits have been legislated in some communities for a considerable time. Similarly, industrial and environmental noise control has been practiced on a specialty basis for a relatively long time; however, it remained for the Second World War and the period following it to bring an ordered technological approach to the problem of noise. This paper attempts to present a reasonable view of the historical development of the understanding of noise control technology and its impact on the education process.
A noise control course for undergraduates
Authors: Hemond Conrad
Published: October 2005

The teaching of a course in Noise Control to undergraduate engineers provides one of the elements to be included in a design sequence of courses. The approach to teaching the course can either emphasize theories of noise control or can provide a “hands on” experience with an existing noise control problem. In either event, the course, offered to Seniors only, must involve analytical procedures, design analysis, a projected solution or steps heading to a solution and often, as time permits, the building of a prototype to illustrate the solution. Analytical procedures involve the separation of air borne sound from structure borne sound. This calls for a prior knowledge of the fundamentals of vibrations. Design analysis involves all of the students' background training in engineering courses; while the projected solution must include an evaluation of economic factors. A detailed description of the course as offered at the University of Hartford will be presented as well as a limited survey of what other Colleges are doing.
T-matrix analysis of the resonances in sound scattering from droplets
Authors: Tanglis E. , Gaunaurd G. , Überall H.
Published: October 2005

A T-matrix code suitable for acoustic scattering has been developed and used to study the resonances present in water droplets in air, whenever they scatter incident sound energy. The numerical determination of the resonance portions of the back-scattering amplitudes is compared to exact analytical expressions suited to this case [J. George, J. Acoust. Soc. Am (in press)], and excellent agreement is found. Several resonances (i.e., fundamental and overtones) present in several of the initial modes have been computed and displayed for various combination of substances inside and outside the droplet. The analysis is useful in the resonance study of sound scattering by aerosols and fogs. [H. Überall is also at Catholic University, Washington, DC 20064 and was additionally supported by Code 421 of ONR.]
An optoacoustic system for the measurement of low concentrations of atmospheric pollutants
Authors: Wright Wayne M. , Stedman Donald H.
Published: October 2005

The optoacoustic effect, through which absorption of chopped optical energy results in the production of sound at the chopping frequency, has become an important analytical tool during the past decade. High-power lasers, operated at visible and infrared wavelengths, have made possible the generation of measurable acoustic signals through optical absorption by a variety of gases as well as by aerosols and solid materials. Device optimization has been attempted by a number of researchers. Elements of the problem are discussed here in the context of a system intended for the measurement of concentrations of nitrogen dioxide as low as 1 part in l09. Of concern are the use of an acoustically resonant gas cell, reduction of extraneous sound generated where the chopped laser beam passes through cell windows, and enhancement of signal relative to acoustic and electronic noise.
Easy-to-handle holocamera for acoustic and bioacoustic studies
Authors: Greguss Pál
Published: October 2005

That optical holography can be a helpful tool in the study of acoustic phenomena both in engineering and bioacoustics is well demonstrated in literature. Nevertheless, holographic metrology is not used in acoustic research as widely as it could be if easy-to-handle holographic cameras were available. Based on a forgotten idea [R. Vadewarker and K. Snow, Appl. Phys. Lett. 10, 35–36 (1967)] we have developed an easy-to-handle camera which can be attached directly to any laser in such a way that hologram recording is practically in line, but the resulting hologram can be reconstructed as if it were off axis. This holocamera has been used to study the particle formation in an acoustic fountain, and to demonstrate how the target behaves when a bat's ultrasonic signal package impinges on it.
T-matrix analysis of the resonances in sound scattering from droplets
Authors: Tanglis E. , Gaunaurd G. , Überall H.
Published: October 2005

A T-matrix code suitable for acoustic scattering has been developed and used to study the resonances present in water droplets in air, whenever they scatter incident sound energy. The numerical determination of the resonance portions of the back-scattering amplitudes is compared to exact analytical expressions suited to this case [J. George, J. Acoust. Soc. Am. (in press)] and excellent agreement is found. Several resonances (i.e., fundamental and overtones) present in several of the initial modes have been computed and displayed for various combinations of substances inside and outside the droplet. The analysis is useful in the resonance study of sound scattering by aerosols and fogs. [H. Überall is also at Catholic University, Washington, DC 20064 and was additionally supported by Code 421 of ONR.]
Pitch shifts associated with partial masking
Authors: Burns E. M. , Oesterle E. L.
Published: October 2005

The change in pitch of a pure tone induced by the simultaneous presentation of a broadband noise is often thought to be related to the “partial masking” (loudness reduction) of the tone by the noise. This assumed relationship was investigated by determining partial masking and pitch shifts for equivalent conditions in the same subjects. Both the reduction in loudness and the reduction in (nonsimultaneous) masking effectiveness of fixed intensity pure tones were measured as a function of noise spectrum level (N0) and were found to be roughly equivalent, as shown by Houtgast [Acustica 30, 214–221 (1974)]. The pitch shifts of the tones, as a function of N0, were also determined. Finally, pitch-intensity functions were obtained for the pure tones. The results show a definite correspondence between the amount of pitch shift and the amount of partial masking. However, neither the magnitude nor the direction of pitch shift is predictable from the pitch-intensity functions by assuming that the partial masking is equivalent to a simple reduction in intensity of the pure tone. [Research supported by NINCDS.]
Dichotic difference edge pitch
Authors: Klein M. A. , Hartmann W. M.
Published: October 2005

The Huggins pitch effect is created by dichotic broadband noise with interaural phase varying from 0 to 2&;pgr; over a narrow frequency range. The sensation of pitch, corresponding to the frequency of the phase shift region, is usually understood as the result of a binaural differencing operation. We report here a pitch effect created by dichotic broadband noise with interaural phase varying from 0 to π over a narrow range, creating an edge in a difference channel. This stimulus produces a pitch close to the phase shift region. It requires practice, alternating the dichotic noise with a probe tone, to hear the effect. For experienced listeners the pitch sensation is similar in nature and strength to the Huggins pitch. It is strongest for shift frequencies in the 350–800 Hz range. It is present for noise at 40 to 60 dB and for shift region widths which are 10%, 5%, or 12% of the center shift frequency. Pitch matching experiments find that the spread of matches is 1%–2% of the shift frequency, as for Huggins pitch, and that the pitch does not depend upon the direction of the shift. [Supported by the NSF.]
Ear dominance for pitch is not a result of binaural diplacusis or selective attention
Authors: Yund E. W. , von Blanckensee H. , Efron R.
Published: October 2005

It has been suggested that the phenomenon of ear dominance for pitch [E. W. Yund and R. Efron, J. Acoust. Soc. Am. 62, 607–617 (1977)] might be a manifestation of binaural diplacusis and/or selective attention. To test the first possibility, we first measured each subject's diplacusis and then measured his ear dominance with dichotic stimuli in which the frequencies of the tones were chosen to exactly compensate for his binaural diplacusis. Subjects showed essentially the same ear dominance for these diplacusis-compensated dichotic tone pairs as they had for similar stimuli without any diplacusis correction. Thus, the ear dominance in these subjects was not due to their binaural diplacusis. To test the second possibility, that ear dominance is due to selective attention, we performed the ear dominance experiments with (diplacusis-compensated) dichotic tone pairs having such a small frequency difference (Δf) that the subject could not discriminate these from binaural pure tones. Subjects showed the same ear dominance for dichotic tone pairs with these small values of Δf as they had for tone pairs with larger values of Δf. With larger Δf's, where two pitch components can be heard, it could be argued that the subject might selectively attend to one component. However, at small Δf's, where the dichotic stimuli are indiscriminable from binaural pure tones, selective attention cannot account for ear dominance.
Generation of emotionally expressive sounds from the dynamic forms of expressive finger pressure: How is expressive touch transformed to expressive sound?
Authors: Clynes Manfred , Dobkin Mark
Published: October 2005

Transduced finger pressure expressions of Anger, Hate, Grief, Love, Sex, Joy, and Reverence (Ann. N.Y. Acad. Sci. 220(3) (1973)] were used as frequency and amplitude modulation envelopes (beginning and ending in silence) of a sinusoidal sound. Experiments were designed to determine what transformation the dynamic forms (essentic forms) produced by finger pressure require, to express like emotional qualities sonically. Sign and depth modulation were found to be specific for each emotion. The dynamic form itself required no modification for frequency modulation, only modulation depth scaling. Optimal ratio of frequency to amplitude modulation varied for different emotions, being least for love and greatest for joy. Both original and sonic forms were correctly recognized by a large majority of 200 subjects. Males and females did equally well. Thus, emotional expression using finger pressure produces a similar emotional expression in sound when its frequency and amplitude modulates a sinusoidal carrier tone in the manner determined, arguing for a common origin in brain function of both touch and sound expressive forms.
Loudness adaptation under free-field listening
Authors: Canévet G. , Germain R. , Marchioni A. , Scharf B.
Published: October 2005

Previous reports [D. Fishken et al., J. Acoust. Soc. Am. Suppl. 1 61, S61 (1977); B. Scharf and T. J. Horton, J. Acoust. Soc. Am. Suppl. 1 63, SI6 (1978)] of loudness adaptation based upon the method of successive magnitude estimation showed that the loudness of a steady high-frequency tone presented through earphones decreases with duration provided the tone is within 20 to 30 dB of threshold. Tones below about 1 kHz and also white noise show much less adaptation. These measurements have been extended to freefield listening. Seated in an anechoic room with his head held steady. O faced a loudspeaker 3.7 m away. Tones were each presented for 3 min at l0 dB above threshold. Every 20 s a light came on for 2 s. The O assigned a number corresponding to the loudness of the tone during the 2-s interval. Results from 26 Os showed that the loudness of a 4-kHz tone decreased after 2 min by 60% and after 3 min by 76%. These values are similar to those measured previously for earphone listening. Tentative results at 8, 10, and 12 kHz suggest somewhat less adaptation at these higher frequencies. Why loudness adapts at low levels and high frequencies and not otherwise remains a mystery. [Research supported in part by NIH.]
Pure-tone intensity discrimination as a function of frequency, level, and duration
Authors: Wier C.
Published: October 2005

Reports on intensity discrimination as a function of duration typically describe performance at only one or two low frequencies. Henning (1970), however, provided intensity-discrimination data as a function of signal duration for 85 dB SPL tone bursts from 250 to 8000 Hz. As stimulus duration decreased, Henning found the intensity difference limen increased more rapidly for low-frequency, than for high-frequency tone bursts. Intensity-discrimination data for relatively long-duration signals (⩾100 ms) show no effect of frequency (Jesteadt et al., J. Acoust. Soc. Am. 61, 169 (1977)]. An attempt was made to resolve this discrepancy by replicating and extending Henning's experiments. Intensity difference limens were obtained with 250-, 1000-, and 4000-Hz digitized sinusolds at durations from 4 to 256 ms. Adaptive and constant-stimulus, 2IFC psychophysical procedures were used and signals were presented at several intensity levels. The results are compared with the predictions of some relevant models of intensity discrimination. [Research supported by PHS Grant No. RR-07096 awarded to the University of Washington.]
High-frequency measurement of the elastic modulus of rubber by the Schlieren method
Authors: Hayek S. I. , Stanic S.
Published: October 2005

High-frequency measurements of the complex Young's modulus was achieved by use of Schlieren photography. A sample plate is immersed in a water tank and insonified by an acoustic beam. A laser beam is expanded and used to illuminate the acoustic field at right angles. The resulting diffraction of light by the sound field is imaged by a video camera. Calibration of the light intensity with the sound intensity gives a quantitative measurement of the sound intensity in the acoustic medium. Thus, the incident, reflected, and transmitted wave intensities are measured. These data are used to compute the complex Young's modulus of the rubber sample. Measurements were made for frequencies between 100 kHz and 2 MHz for a sample of rubber.
Measurement of dynamic elastic moduli
Authors: Edelman S. , Newman N.
Published: October 2005

A nonresonant method for measuring the dynamic strength of materials under load has been devised. Some preliminary measurements have been performed. The method makes it possible to determine, from measurements on a single specimen, both the real and imaginary parts of both the dynamic Young's modulus and the dynamic shear modulus as continuous functions of frequency and static load. The frequency can be varied over a wide range and the static load can be varied from a large compressive value through zero to a large tensile value. The measured data consist of the amplitude and phase of the strain at three points on a specimen in the form of a long thin rod. The locations of the two outer points are chosen arbitrarily and the intermediate point is located halfway between them. A small change in the mathematical development allows vibration amplitude, velocity, or acceleration to be measured, rather than strain.
Determination of the dynamic shear modulus and loss factor of rubber
Authors: Gaunaurd G. , Scharnhorst K. P. , Überall H.
Published: October 2005

We have recently developed a new resonance theory for the scattering of compressional waves by fluid-filled spherical cavities in viscoelastic materials, and have applied it to the study of the resonance frequencies and widths of peaks in the (monopole) f0pp scattering amplitude. Using this theory, which is the viscoelastodynamical counterpart of the Breit-Wigner formalism of nuclear scattering theory, we find that (i) the relative half-width of the peaks depends linearly on the resonance frequency, (ii) the shear-absorption parameter of the viscoelastic material containing the cavity can be determined from the slope of a straight line fit to the data. This determination is possible precisely because our theory realistically accounts for absorption in the material, and thus its predictions compare favorably with experimentally measured data. Finally, the theory gives a self-consistent way to verify the weak absorption assumption inherent in the prediction. [H. Überall is also at the Physics Department, Catholic University, Washington, DC 20064, additionally supported by Code 421 of ONR.]
Acoustic resonances in a viscous fluid layer
Authors: Fiorito Ralph , Madigosky Walter , Überall Herbert
Published: October 2005

In previous publications [J. Acoust. Soc. Am. 65, 9 (1979); J. Acoust. Soc. Am. 66, 1857 (1979)] we have shown that the acoustic transmission T and reflection coefficient R of a fluid layer and an elastic layer imbedded in another fluid can be written in the form of a sum of resonance terms. Our resonance formalism provides an explicit determination of the position, width, and strength of each individual resonance contribution. In the work presented here we have extended the resonance theory of a fluid layer to include visions effects, by the introduction of a complex phase velocity of sound in the layer, the imaginary part of which is written in terms of an absorption loss factor. Viscosity manifests itself in a shift of the resonance positions as compared to those of the non-viscous layer, and in a broadening and frequency dependence of the resonance widths. These effects can be used to determine the material parameters and the loss factor of the layer. Numerical examples will be presented. [H. Überall is also at Catholic University, Washington, DC 20064, additionally supported by ONR Code 421.]
Dynamic properties of extensional damping materials
Authors: Hanson William J. , Hampel Gary A.
Published: October 2005

The properties of approximately 60 commercial extensional damping materials are summarized in this paper. These data were obtained in order to evaluate all materials using a standard test technique. This would enable one to make direct comparisons of products resulting in optimum selection of materials for specific applications. Testing was conducted in accordance with the proposed ASTM standard on “Measuring Vibration Damping Properties of Materials.” The data were obtained with a complex modulus apparatus using the Oberst beam technique. Values for Young's modulus and loss factor, are presented for each material as a function of temperature and frequency. The test range for these parameters was approximately 5–100°C and 180–3000 Hz, respectively. The test apparatus consisted of cantilevered composite beams mounted in a clamping fixture within an environmental chamber. White noise was provided as an excitation source through a noncontacting transducer. A two-channel fast Fourier spectrum analyzer was used to obtain information on phase and coherence as well as the half-power bandwidth. The analyzer was equipped with a frequency translator for improved resolution.
Measurement of dynamic moduli and loss factor of viscoelastic materials using the gas bearing electrodynamometer (GBE)
Authors: Hargens C. William
Published: October 2005

The gas bearing electrodynamometer (GBE), smaller than a baseball, has now reached a state of perfection and proved itself of sufficient value in a number of medical, biological and materials applications to deserve wider publication than heretofore. It fills an important gap in the spectrum of measuring devices capable of analyzing the mechanical characteristics of materials, but more especially soft, energy-absorbing solids. The GBE is an answer to the problem of measuring small forces acting in soft, highly compliant materials where the intervention of a stiffer transducer would mask the modulus or effect being studied. For example, a strain gauge operating with a sensitive electric bridge can be used to measure small forces, but this type of transducer or any flexural element upon which it is mounted will be inherently quite stiff with even minor deflection. While the spring rate of any such gauge or combination is high, the GBE, on the other hand, can have a spring rate which approaches zero. The force and displacement of the GBE can be readily registered electrically. The displacement can be several millimeters or more without the specimen undergoing more than a minute stress. This is important for the study of biological or other soft materials. Frequently in such cases the effects one wishes to observe without imposing large forces require that considerable displacements occur. Furthermore, soft tissue or other viscoelastic material may show nonlinear stress-strain characteristics only after the application of larger and more rapid oscillations than a conventional testing machine can achieve, and the cumbersomeness of such equipment makes its use in tests upon delicate substances impractical.
The perceptual classification of speech and nonspeech sounds
Authors: Jusczyk Peter W. , Smith Linda B. , Murphy Christopher
Published: October 2005

It is well known that the formant transition cues which signal the presence of [b] and [d] vary greatly according to vowel context [Liberman et al., Psychol. Rev. 74, 431–461 (1967)]. Yet, listeners nonetheless classify these different physical cues as belonging to the same phonetic segment. The present study focusses on the way in which adults are able to utilize formant transition information in perceptual classification tasks. Is there information in the formant transition that cues [b]'s and [d]'s in various vowel contexts which adults can use to form consistent groups in perceptual classification tasks? Do the perceptual groupings obtained conform to phonetic categories? Is formant transition information presented in a nonspeech context (as either two or three formant chirp patterns) grouped in the same way as when it occurs in the context of speech syllables? Our results suggest that (1) though classification according to phonetic categories is not subjects' preferred mode of grouping they can be instructed to classify in this way; (2) different groupings occur for the speech and nonspeech contexts; (3) there is sufficient information in three-formant chirps to form groups based on phonetic categories. [Work supported by N.S.E.R.C. and NSF.]