bluuebunny/crossref_metadata_2025 huggingface dataset:
The first 100 years of “voiceprinting.”
Authors: Truby Henry M.
Published: October 2005

“Voiceprinting,” appropriately defined, is the sound-spectro-graphic technology aspect of speech and voice individuation. A speechsound spectrogram is at once a voicesound spectrogram, since voice is the biophysical instrument of speech. Speaker individuation, known widely today as voice identification, has been with us throughout history. Technological implications of speech/voice idiosyncrasy have been sighted, and/or explored instrumentally, for at least 100 years. Here listed is a partially annotated chronology of authors and publication dates significant for this author's 30-yr commitment to the development of an instrumental speaker-individuation technology: Alexander Melville Bell (Visible Speech: The Science of … Physiological Letters, etc.): 1867; Galton (“fingerprinting”): 1892 (cf. Neumueller GREW—1684); Scripture!: 1902 (653 pp.); Liddell! (The Physical Characteristics of Speech Sound): 1924–1925–1927; Paget: 1930; Scripture (“vowel track analysis”): 1933; Lacerda: 1932–1934; Steinberg!: 1934; Liddell: 1940; Gray/Kopp! (“Voice Print Identification,” 41 pp., explicit): 1944; Potter: 1945–1946; Steinberg/French!: 1946; Koenig/Dunn/Lacy: 1946; Kopp/Green!: 1946; Potter/Kopp/Green!: 1947; Joos! (Acoustic Phonetics): 1948; Truby: 1957-1959!-1960 (“cryprinting”); Fant: 1960; Cummins/Midlo (“Dermatoglyphics”): 1961; Truby: 1962; Kersta (“Voiceprint Identification”): 1962; Garvin/Ladefoged (“Speaker Identification … Speaker Recognition”): 1963 (variously: 1950–1970: Peterson, Stevens, Flanagan, Fant, Lehiste, Truby); Tosi et al.: 1971; Smrkovski: 1974; plus the continuing, practical, day-by-day, field-laboratory investigations of Hall, Smrkovski, Chiari, Richardson, Tosi, Truby, and other Certified Voice Identification Examiners: esp., 1972–1977. And whom, after all, does the relevant “scientific community” comprise … in controversial “Voiceprint” affairs? [Supported by International Association of Voice Identification.]
Processing spatially aliased arrays
Authors: Hinich Melvin J.
Published: October 2005

A linear array can detect a plane wave signal at a wrong bearing if the signal wavelengths are shorter than twice the distance between the closest adjacent sensors. This phenomenon, called spatial aliasing, is most pronounced when the bearing is near endfire. This paper presents a method for correcting spatial aliasing of broadband signals using the frequency-wavenumber approach to array processing. Also presented is a method for averaging the ω-κ spectrum values that will give a more accurate bearing estimator than the method presented in a 1973 JASA article by Clay, Hinich, and Shaman [J. Acoust. Soc. Am. 53, 1161 (1973)]. The methods discussed in this paper can be used for a sparse unequally spaced array which is detecting a dispersive signal.
Simple optimum data windows for digital signal processing
Authors: Burgess J. C.
Published: October 2005

The spectral representation of a finite–length sample from a sinusoidal signal can be regarded as a convolution of the spectral representation of the infinite-length signal and a finite-length “window.” The spectral representation of the window consists of a main lobe and a sequence of side lobes. By changing the shape of the window, maximum side lobe amplitude can be decreased. The cost is that main lobe amplitude is increased. Window design consists in finding an acceptable trade-off between these two effects. A useful and practical criterion for design is that the main lobe be the narrowest possible for a specified ratio of maximum side lobe amplitude to main lobe amplitude subject to the condition that the window is described by a Fourier series having very few non-zero coefficients (e.g., for a ratio of −60.00 dB, B0=1, B1=0.534 373, B2=0.051 800, B3=−0.000 051, B−ν=Bν. The resulting family of data windows have the narrowest main lobes of any known to the author.
Characteristics of acoustic signals from explosive line charges and point charges
Authors: Jensen H. M.
Published: October 2005

For certain applications in the ocean, acoustic signals are generated by detonation of small explosive charges. These charges may be in the form of a compact mass of explosive material or as distributed plastic line charges. The characteristics of the acoustic signal obtained depends on the particular configuration. Measurements were made of the signals received in the ocean from both types of charges under the same conditions. Comparisons are made of the acoustic signatures, received energy levels and frequency spectra.
Theory of a discrete element method for modeling parallel-coupled muffler components
Authors: Sullivan J. W.
Published: October 2005

Parallel-coupled muffler designs incorporating lengths of perforated tubing, such as concentric tube resonators (bean cans) and expansion chambers with perforated tubes extending into the chamber, cannot be modeled by traditional methods. In a recent paper, [J. W. Sullivan and M. J. Crocker, J. Acoust. Soc. Am. 60, S123(A) (1976)] a closed form solution for the transmission loss of a concentric tube resonator was presented, but the solution was restricted to the perforate having a constant specific impedance along the length of the tube. If the perforate impedance should vary along the tube either by design or by nonlinear effects a closed form solution is no longer possible and it then becomes necessary to resort to an approximate solution. One such solution is presented in which the tube and its backing volume are subdivided into discrete elements (slices) each described by a 4 × 4 transmission matrix. The advantages and disadvantages of this rather simple method compared with finite difference or finite element methods are discussed.
Ultrasonic shear viscosity equation for a liquid drop
Authors: Shalis Edward V.
Published: October 2005

A method to measure viscosity of liquids of small volume, such as drops, is developed by approximating the shear vibrations of finite quartz bar by a sam of zero-order mode functions. Vibrations of these natural modes are represented by an equation similar to that of a point mass vibrating with resistance and compliance. The viscosity equation is derived from knowledge of the energy loss when the crystal is vibrating in air and when a liquid drop is placed in its surface. We consider the case when the applied force is removed and the crystal vibrations are allowed to decay exponentially with time. A free liquid is then placed on the top surface and the Stokes wave equation is used to determine the velocity field. Work performed by the crystal surface on the viscous liquid is determined from the reaction force exerted by the fluid. The final viscosity equation is expressed in terms of the increase in loss factor, the liquid contact area, crystal frequency, liquid density, correction factor allowing for dilatational motion, and crystal mode mass. All parameters, except density, must be determined experimentally.
Acoustic levitation of red blood cells
Authors: Apfel Robert E. , Haltiwanger Mary Ann , Wagner Victoria
Published: October 2005

The banding of red blood cells in an ultrasonic standing wave has been observed in vivo in the blood vessels of chick embryos [M. Dyson et al., Ultrasound in Medicine 1, 133 (1974)] and in whole and diluted blood in vitro [N. Baker, Nature, Lond. 239, 398 (1972)]. This banding has been attributed to forces generated by acoustic radiation pressure. If this force is balanced by the gravitational forces, the red blood cells (rbc's) will be levitated. It is interesting to note that in the absence of flow the position of levitation is independent of the size or shape of the rbc's for acoustic wavelengths large compared to rbc size and depends only on rbc density and compressibility in relation to the surrounding host medium. Therefore the position at which bands of rbc's form can be used to obtain information about their mechanical properties. We shall describe our system for levitating red blood cells (a movie will be shown), and we shall discuss how information about rbc compressibility can be deduced. [Work supported by ONR and Yale Summer Research Program.]
Generation of ultrasound at metal-electrolyte interfaces
Authors: Borsay Frank , Yeager Ernest
Published: October 2005

When a radio frequency potential difference is applied across a metal-electrolyte interface, ultrasound of the same frequency should be generated at the interface. This effect is expected on the basis of uncompensated volume changes in the electrolyte adjacent to the metal surface. The effect has been detected for the first time at ∼ 500 kHz and preliminary results are reported. The measurements have been made in a specially designed electroacoustic cell with gold electrodes in acid and alkaline electrolytes. The sound generated within the cell propagates into a large tank where it is detected with a ceramic hydrophone, calibrated separately against radiation pressure measurements. Pulse modulation has been used to discriminate against any electromagnetic crosstalk. The sound intensities although small (∼10−9 W/cm2) are easily detected and depend on the dc bias potential applied to the interface and the electrolyte composition. The effect is very sensitive to impurities, especially organics. This effect is a promising tool for the study of metal-electrolyte interfaces. Methods for greatly enhancing the effect will be discussed. [Research sponsored by ONR.]
Experimental studies of the first shear (Sezawa) mode and the fundamental Rayleigh mode
Authors: Bray D. E. , Egle D. M. , Reiter L.
Published: October 2005

The first shear mode (Sezawa mode) and the fundamental Rayleigh mode have been identified as they propagated through the work-hardened layer on the top surface of used, steel railroad rail. Longitudinal wave velocities and densities are very nearly equal for the work-hardened layer and the subadjacent layer. The ratio of shear wave velocity in the upper layer to that in the subadjacent layer is near to 0.95. Experimental data obtained at several frequencies (0.5–2.0 MHz) showed agreement with expected velocities for a layer thickness ranging from 3 to 5 min. [ Work supported by DOT.]
Calculation of isothermal and viscous effects in acoustic tubes
Authors: Zuercher J. C.
Published: October 2005

A simplified derivation of the per unit length acoustic impedance for a cylindrical tube is described which includes both viscous and isothermal effects. The resulting expressions (which include complex Bessel functions) are reduced to algebraic terms that allow rapid computation of system frequency response functions on a digital computer. This approach retains the separation between series (viscous) and parallel (thermal conduction) tube losses. Comparison between theory and experiment for the frequency responses of tubes terminated in cavities or in a miniature microphone shows good agreement. A particular tube and miniature microphone system is selected that graphically illustrates the relevant differences between, and the indicated improvement of, this approach over more traditional calculations of tube losses. For convenience, computer plots of characteristic impedance, attenuation, and time delay are provided for “small” tubes.
Optimization of magnetically coupled drive of the ear
Authors: Mooney John A. , Moushegian George
Published: October 2005

The ear level hearing aid represents the ultimate in basic hearing aid configuration. This paper presents a feasible electromagnetic drive approach that virtually eliminates acoustic feedback problems of ear level aids as well as providing precise low distortion performance heretofore unavailable in a miniature aid. New magnetic materials of the platinum-cobalt and rare earth cobalt class make possible the realization of the goal of 100 dB re 0 dB = 0.0002 dyn/cm2 sensation level for 1 mW input as needed for low battery drain. These acoustic levels are measured via frequency following potentials (FFP) as well as by the microphonic cochlear potentials recorded at the round window. Suggested additional features are covered as well as the culminating role of electret microphones, lithium batteries, and modern IC fabrication techniques to make possible a programmable aid of unprecedented quality. [Supported by NIH grant.]
Effect of fillers on acoustic properties of silicone rubber at ultrasonic frequencies
Authors: Corsaro R. D.\ , Klunder J.
Published: October 2005

We have had a recurring need for molded articles (wave guides) and thin anechoic coatings, composed of rubbers with well defined and continuously variable acoustic properties. To fill this need, we have measured the dependence of various acoustic properties (sound speed, density, absorption) on the amount and type of filler added to RTV 602 silicone rubber. Both high impedance (ferric oxide, lead) and low impedance (glass and backlite microballons) modifiers were added, in two and three component mixes. A diluent (toluene) was found, which had no observed effect on the acoustic properties of the resulting rubber. Acoustic measurements were made using thick (molded) slabs, as well as thin (sprayed) coatings. In the latter cases, sound speed and absorption is evaluated using the measured frequency dependence of the coating's impedance. In all cases, we find that density and sound speed is well described using ideal mixture theory, providing the geometry of the microballons is taken into account. Absorption is described by simple phenomenological equations, and compared with theoretical predictions.
Dual processing versus response-limitation accounts of categorical perception: A response to Macmillan, Kaplan, and Creelman
Authors: Perey A. J , Pisoni D. B.
Published: October 2005

At the last meeting of the Society, Macmillan, Kaplan, and Creelman argued that measures of discrimination typically obtained in speech perception experiments employing single-interval absolute-identification tasks do not reveal the “true sensitivity” of the observer because only a very small number of response categories are permitted and identification into these putative phonological categories is often without error. In the present paper we present the results of two experiments, one employing synthetic stop consonants and the other employing synthetic steady-state vowels, in which observers were permitted to use a relatively large number of response categories in an absolute-identification (AI) procedure similar to that used by Braida and Durlach. Discrimination performance in the identification task was then compared to discrimination obtained in the traditional ABX format in order to assess the correspondence between the two measures. The results revealed systematic differences in discrimination between consonants and vowels and between AI and ABX procedures. While improved discrimination performance was observed in the AI task for vowels by permitting a larger number of response categories in identification, the same effects were not observed for stop consonants. Our findings suggest that the account of categorical perception offered by Macmillan et al., in terms of response limitation in identification, is not a sufficient and viable alternative to previous accounts of categorical perception in terms of dual coding models which postulate separate levels of coding information in speech perception. [Supported by grants from NIH and NIMH.]
Speech synthesis by dyadic interpolation of spectral parameters
Authors: Shadle Christine , Atal Bishnu
Published: October 2005

Recent work of Olive and Spickenagel on dyadic interpolation of pseudoarea parameters derived from linear prediction analysis has shown that speech synthesized from these parameters suffers very little distortion due to the dyadic interpolation. This raises a question: Can other acoustic parameters, such as the power spectrum of the speech waveform, be similarly interpolated? The spectrum is of special interest because speech can be synthesized in real time from spectral parameters on a readily available programmable digital filter. To study this question a speech analysis-synthesis system using spectral parameters (samples of power spectra at different frequencies) was simulated. These parameters were determined from the speech signal at every dyad boundary, and interpolated for intermediate values. Dyad boundaries (representing the limits of transition regions between phonemes) were determined interactively. Informal listening tests comparing synthetic speech with and without dyadic smoothing showed slight degradation in the smoothed speech. The degradation results from nonlinear variations of spectral parameters within some dyads. Methods for handling these nonlinearities will be discussed. The results of our study suggest that dyadic interpolation works as well for spectral as for area parameters.
Phase interactions resulting from the avain interaural pathway
Authors: Rosowski J. J. , Saunders J. C.
Published: October 2005

Acoustic measures of sound transmission across the effective interaural pathway (the interaural pathway and a tympanic membrane) have described a 20–30 dB attenuation of frequencies within the audible range of the chicken [J. J. Rosowski, J. Acoust. Soc. Am. 61, S3(A) (1977)]. The present report is concerned with the phase delay imposed by the effective interaural pathway. Cochlear microphonic responses were recorded in young chickens under conditions of homolateral or contralateral sound stimulation. The stimuli consisted of continuous pure tones with frequencies between 125 and 6300 Hz. The phase response of the CM relative to the phase of the stimulus at the directly stimulated tympanic membrane was determined. Comparison of the CM phase response between conditions of homolateral or contralateral stimulation yielded a measure of the effective phase delay resulting from the interaural pathway. The interaural change in phase (Δφ) for frequencies between 125 and 500 Hz was 180°. This finding suggests that the interaural pathway allows a stimulation of the opposite tympanic membrane in the reverse direction of normal stimulation. At higher frequencies the interaural Δφ increased such that a Δφ of 800° was measured at 6300 Hz. These phase delays are much greater than would be expected from the interaural distances involved. Binaural stimulation resulted in complex interactions of the two stimuli which brought about changes in recorded CM amplitude and phase. A possible relationship between these interactions and localization phenomena will be discussed. [Work supported by NSF.]
Short-latency evoked response correlations of psychophysical phenomena: Preliminary results from forward masking studies
Authors: Stanny R. R. , Elfner L. F.
Published: October 2005

Human wave V (8 msec latency) responses were recorded under forward masking conditions using vertex-mastoid electrodes. Masking and masked stimuli were either noise-burst clicks or sinusoids. When pairs of 1 msec clicks are presented monaurally at 75 dB SPL, the masked-stimulus wave V response is reduced by about 93% when the interstimulus interval is 1 msec. Amplitude recovery is rapid and largely complete by 10 msec. 4 msec sinusoids presented singly at constant 55 dB sensation levels produce a bandpass frequency response function with a peak at about 3 kHz. When frequency is reduced below about 9 kHz, the wave V complex separates into two components: A fast positive defection with a stable latency of about 8 msec and a slower biphasic response with a latency inversely related to frequency (the later portion of this wave appears to overlap the postauricular muscle response). Forward masking of these responses is restricted to the spectral region of the masking sine wave; work directed toward determining the shape of the wave V “filter” is currently under way.
Model to assess the impact from individual exposure to single-noise sources
Authors: Jaskun P. A. , Manning J. E.
Published: October 2005

A model has been developed to predict the statistical distribution of cumulative exposure and impact due to single-noise sources as a function of individual lifestyle. The model is particularly suited to stationary noise sources in a dynamic environment and has been implemented into an interactive computer program. Results have been generated for a typical consumer product. For some representative human scenarios and corresponding situations of exposure to product noise, separate distributions of people with respect to (a) (p/p0)2 from the source and (b) hours of exposure were generated. The distributions were calculated using indoor and outdoor acoustics theory and statistical descriptions of input parameters such as numbers of the product in use, noise emissions by various categories of the product, types of dwellings in which people live and work, and geographical considerations. The cumulative exposure expressed as Leq(24) was basically determined from the sum of the joint distributions of (a) and (b) over all exposure situations and all scenarios. The distribution of impact was determined by computing cumulative exposure with and without inclusion of the product noise. [Work supported by EPA.]
Research on conventional hearing aids
Authors: Studebaker G. A. , White R. E. C. , Levitt H.
Published: October 2005

Technical advances and changes in the demographic characteristics of hearing aid users over the past three decades have revived interest in the age-old question of how best to shape the frequency-gain characteristic of hearing aids. Several experimental approaches to determining optimum hearing aid characteristics are described. A number of problems have been encountered, including specification of overall frequency-gain characteristics from sound field to eardrum, acoustic feedback, and nonlinear distortion. Approaches to these problems are discussed. [The research supported by Contract No. NIH-NO1-NS-4-2323 and Grant No. NS 13514 from NINCDS.]
New results on multichannel amplitude compression for the hearing impaired
Authors: Lippmann Richard P. , Braida Louis D. , Durlach Nathaniel I.
Published: October 2005

Experiments were conducted on five listeners with sensorineural impairments and reduced dynamic ranges using 16-channel computer controlled, amplitude compression systems. Each subject was tested with two compression systems and, for reference purposes, four linear systems. One of the compression systems was chosen to restore normal equal loudness contours; the other employed reduced high-frequency emphasis and reduced compression ratios. The four linear systems differed only in the frequency-gain characteristic (orthotelephonic plus three characteristics with high-frequency emphasis that were expected to produce better results than orthotelephonic). The six systems were compared on each of the five subjects using nonsense CVC monosyllables and sentence material spoken by male and female talkers and presented in quiet/anechoic and noisy/reverberant environments at the most comfortable level for each listener. The principal results of these tests were: (1) The linear system with high-frequency emphasis produced substantially better performance than the orthotelephonic system; and (2) neither of the two compression systems led to significantly better performance than the best linear system. In considering these results, it should be noted that (a) the long-term level of the speech material was held constant before processing, (b) the subjects suffered from only moderate losses, and (c) only two compression systems were tested. If one takes account of the differences in the linear systems to which the compression systems were compared, these results are consistent with those of Villchur [J. Acoust. Soc. Am. 53, 1646–1657 (1973)], and of Barfod [Reports No. 4 and 11, Acoust. Lab., Tech. Univ., Denmark (1972, 1976)]. [Work supported by NIH Grants 5 R01 NS12846 and 5 T01 GM01555.]
Evaluation of spectrally oriented tactile speech aids
Authors: Sparks D. W.
Published: October 2005

A renewed interest in the development of tactile speech aids has been generated in the last four years. The revitalization of research in this area stems primarily from three sources; (1) there is a highly sophisticated technology which is available to engineers for the fabrication of these devices, (2) it is now accepted that extensive training is necessary before subjects achieve significant benefit in the use of tactile aids, and (3) an extensive corpus of knowledge provided by basic research in several fields has provided guidelines for the design of more efficient speech-to-tactile transform hardware. Several laboratories across the country are testing versions of spectrally oriented tactile aids. These research efforts will be discussed along with some guidelines for future research in this area.
Sensory parameters of the ultrasonic binaural spatial sensor with particular reference to use by blind babies
Authors: Kay L.
Published: October 2005

The sensory parameters of the ultrasonic binaural spatial sensor for use by blind persons are discussed. These comprise (1) the distance cue coded in kHz/m which can be varied from 1 kHz/m for long (5m) range use to 10 kHz/m for short (0.5 m) range use; (2) the direction cue coded in binaural intensity difference in dB/degree and may be varied in practice from 0.2 to 1 dB/degree giving either a compressed expanded angular resolution; (3) the field of view which may be wide (120°) or narrow (10°). These parameters are discussed to show what choices are available in deciding on the parameters of an aid to be used by a blind baby. It is shown that the effect of motion causing Doppler shifts can be minimized in a baby's aid and greater resolution obtained by the appropriate choice of sensory parameters. It would seem that specialists, similar to opticians or audiologists, are needed in this field to make the choices and fit the sensory aid. Results of work with babies and young children will be discussed.
An absolute coupling between psychological magnitudes of numbers and loudness
Authors: Zwislocki J. J. , Bolanowski S. J. , Capraro A. J. , Goodman D. A.
Published: October 2005

It is usually assumed that, in magnitude estimation and production procedures, subjects assign numbers to sensation magnitudes on ratio scales, i.e., according to ad hoc units. However, S. S. Stevens and others have found that units imposed by the experimenter produce response biases, and Hellman and Zwislocki were able to explain a strong response bias in some of their data by assuming that their subjects tended to pair numbers and loudness magnitudes on an absolute scale. This implies that, through common usage, numbers become associated with psychological magnitudes on a one-to-one basis, and a natural unit develops. Some subsequent experiments confirmed this hypothesis. Present experimental results of loudness scaling performed by several groups of subjects with varying degrees of sophistication reveal an unexpectedly small variability of the median scale units used by the groups and asymmetrical learning effects.
Noise annoyance judgement as affected by intensity of illumination in relation to personality
Authors: Shigehisa T. , Gunn W. J.
Published: October 2005

Annoyance judgement of a series of noise stimuli was made by magnitude estimation under three intensities of illumination. Subjects were classified into three groups in each dimension, based on Eysenck Personality Inventory extraversion, neuroticism, and lie scale scores. Two degrees of octave band energy attenuation, four center frequencies for this attenuation, and three overall intensities constituted the noise stimuli. Intensity of illumination (achromatic) ranged from 0.25 to 12.50 fc in the range of each subject under television viewing (chromatic) in a simulated indoor environment. Intermediate intensity (2.05 fc), ordinary living room brightness, was taken as the control. It was predicted that intensity of illumination influences annoyance judgement, and this influence varies with personality. Results showed a significant interaction between illumination intensity and personality type. Annoyance increased at weak and decreased at strong intensities in introverts (as compared with control); while annoyance decreased at weak intensity in extraverts. Annoyance decreased at weak and increased at strong intensities in emotionally labile subjects; whereas it decreased at strong intensity in emotionally stable subjects. However, annoyance decreased at both intensities in dissimulators, while it increased at strong intensity in nondissimulators. The prediction was verified, and noise spectrum differentiated this prediction.
TTS at 4 kHz among school-age children following continuous exposure to a broadband noise
Authors: Hétu R. , Dumont L. , Légaré D.
Published: October 2005

TTS from a mild noise condition was measured among three age groups: six young adults, ten 12-yr and ten 7-yr old children. All subjects were exposed during 12 min to a broad-band noise at 96 dB SPL delivered through conventional dynamic earphones. TTS was obtained at 4 kHz in both ears 2, 15, and 30 min following the end of exposure. No difference could be observed between the TTS's from the 12-yr group and the young adults. The 7-yr children showed significantly less threshold shift than the older subjects, but on the other hand they appeared to recover more slowly than the latter. The difference obtained between amounts of TTS2 were attributed to the poorer hearing sensitivity of the 7-yr group at the tested frequency, as compared with the 12-yr or the adult subjects.
On the efficiency of 2IFC threshold measurement
Authors: Schacknow Paul N. , Barth Craig T.
Published: October 2005

A tone intensity-discrimination experiment compared the efficiencies of two threshold-tracking rules used with two-interval, forced-choice (2IFC) methodology. Half of the time, a two-right, one-wrong (“2-1”) level-change rule [H. Levitt, J. Acoust. Soc. Am. 49, 467–477 (1971)] tracked thresholds with a binomial probability of 0.707. The remainder of the data were collected under a five-right, two-wrong (“5-2”) rule which tracked 0.736. Stimuli were 1000 Hz tone bursts (100 msec) presented binaurally over headphones at 70 dB SPL. A fixed step size for changes in ΔI (2 dB) was maintained by adding the increment and standard channels in quadrature. Thresholds were determined for sessions of 40, 55, 70, 85, 100, and 115 2IFC trials. Six thresholds were taken at each session size, for each of the two level-change rules. Thresholds were computed as the mean level of ΔI revisited. Sweat factors [M. M. Taylor and C. D. Creelman, J. Acoust. Soc. Am. 41, 782–787 (1967)] were calculated and averaged across the seven subjects for each of the 12 experimental conditions (session-size x rule). The 2-1 rule generated smaller sweat factors, averaged across sessions, and was thus the more efficient rule. An analysis of variance yielded the additional finding that psychophysical efficiency was independent of session size.
Pattern discrimination of tone and tone/glide sequences
Authors: Kerivan J. E.
Published: October 2005

In a previous study we observed that identification of temporal order in computer-generated pure-tone sequences was better than that for tones and glides in sequence [J. E. Kerivan and B. Carey, Percept. Psychophys. 20, 489–492 (1976)]. In continuation, the present experiment studied discrimination performance for pure tone sequences and again for tone/glide sequences. Twenty Ss made same/different comparisons of the order of events ranging from 20 to 60 msec. In one condition pure tones at 713, 1031, 1209, and 1514 Hz were used. In another, two unidirectional glissandi chosen from 466–712 Hz, 714–1208 Hz, and their mirror reversals were substituted for 1031 and 1514 Hz. Discrimination performance was significantly better in the tone/glide condition. It was slightly better for the longer event durations. In each pattern, event position No. 4 was the most important cue in the more difficult discriminations. Thus, when same/different discriminations are made on four event pure tone sequences event position, rate, frequency, and temporal continuities should be evaluated.
Perception of glides in multisyllabic utterances by infants
Authors: Jusczyk P. W. , Copan H. C. , Thompson E. J.
Published: October 2005

Several aspects of the two-month-olds' perception of a phonetic contrast between glides in multisyllabic utterances were explored with the high amplitude sucking paradigm. First, do infants perceive contrasts between glides in the initial (e.g., YADA versus WADA) and medial positions (e.g., DAYA versus DAWA) of multisyllabic utterances? Second, are infants more likely to perceive these contrasts between stressed or unstressed syllables: Our results suggest the following: (1) two-month olds are sensitive to place-of-articulation differences between glides in both the initial and medial positions of multisyllabic utterances; (2) positioning stress on the syllables to be discriminated had little or no effect on the infants' ability to perceive the contrast; and (3) there was no indication that infants were any more sensitive to the contrast in the initial position than in the medial position. Our findings were in complete agreement with those observed previously for infant's perception of stop consonant differences in multisyllabic utterances [Jusczyk and Thompson, Soc. Res. Child Dry. Abstr. (1977)], suggesting that infant's detection of medial contrasts does not depend on the presence of abrupt formant transitions.
Phonetic aspects of “devoiced” stop consonants in children's speech
Authors: Smith Bruce L.
Published: October 2005

Word-final “devoiced” obstruents have frequently been observed in children's speech, but very little descriptive information is available regarding acoustic phonetic properties of such consonants. In order to study developmental characteristics of voicing control during “voiced” and “voiceless” stop closure, five English-speaking 212–3 year olds, five 4–412 year olds, and five adults recorded productions of the nonsense utterances: /bab, bábab, babáb, dad, dádad, dadád, tat, tátat, tatát/. Measurements were made from oscillographic traces, and the data were analyzed in terms of (1) the percentage of all stop productions evidencing “devoicing” during closure, and (2) in the case of devoiced stops, the proportion of closure duration evidencing voicing. Both groups of children revealed more frequent occurrence of devoicing than the adults, and the voiced proportion of devoiced stops was also less for the children than for the adults. It was also observed, however, that the children's “devoiced” stops revealed more voicing than their “voiceless” stop productions. Results are discussed in terms of aerodynamic principles of speech production.
Effects of flaws on the reflection function of elastic bodies
Authors: Flax Lawrence , Dragonette Louis
Published: October 2005

The possibility of detecting the presence of flaws, in elastic cylinders and spheres immersed in a fluid. by means of the change in the reflection function is investigated theoretically. In each of these bodies the flaws are represented by spherical and cylindrical cavities. The behavior of the reflection function as the dimensions of the cavity approach zero is examined.
Multipole resonances in sound scattering from gas bubbles in a liquid
Authors: Sage K. A. , George Jacob , Überall H.
Published: October 2005

Using techniques borrowed from nuclear physics, we have performed calculations of the resonant backscattering of acoustical waves incident upon spherical gas bubbles in a liquid. In addition to the well-known “giant monopole” resonance, we have found a large number of higher-frequency resonances which are either overtones of the monopole or which correspond to both fundamental and overtones of resonances or higher multipolarity. While these higher-frequency resonances are much smaller in strength than the giant monopole, they are prominent with respect to the background, and may be of some importance in sound scattering from gas bubbles in a liquid. We discuss the eigenvalue equation for these resonances and present numerical results of our cross-section calculations. The cross sections are corrected for the effects of depth in the liquid, surface tension of the bubble, and bubble mobility. [K.A.S. supported in part by Office of Marine Technology, NOAA; J.G. and H.Ü. supported in part by ONR Code 421.]
Transient acoustic transmission through a test panel
Authors: Kerwin Edward M.
Published: October 2005

In the measurement of the transmission properties of panels it is usually desirable to make the test panel as small as possible, consistent with the avoidance of edge-diffracted signals at the receiving sensor. The transient response of the panel will delay the attainment of a steady-state transmitted signal. Such a delay shortens the time window available for measurement before the arrival of the signals diffracted from the panel edges. The effect is illustrated analytically for a panel to be tested in water, and comprising a mass sheet (a plate below its critical frequency) and an attached compliant layer. Several sets of systems parameters are chosen, and the approach to steady state is determined as a function of the number of cycles of the excitation. The more sluggish the panel response (due, say, to a lower resonance frequency of the plate mass with the layer stiffness), the more slowly the panel achieves steady-state response at any given frequency. Thus a sluggish panel would have to be larger to be free of edge-diffraction effects.
Application of the geometrical theory of diffraction for predicting farfield radiation patterns from a vibrating rectangular boxlike structure
Authors: Saha Pranab , Pierce Allan D. , Hadden W. James , Usry Gerald R.
Published: October 2005

This paper extends the author's previous paper (presented at the 94th meeting of ASA) on the prediction of farfield sound radiation from a vibrating rectangular boxlike structure resting on the ground from surface acceleration measurements. The lowest-order approximation of the Green's function which was used earlier can describe farfield radiation only for certain ideal points. An improved approximation to the Green's function (with Neumann boundary conditions) can be fabricated to predict the entire far field radiation pattern from the corresponding Helmholtz integral equation solution for the same problem based on techniques related to the geometrical theory of diffraction. The resulting approximate Green's function takes into account the direct waves and the diffracted waves with the assumption that the sound diffracted by more than one edge of the box makes a negligible contribution to the farfield. The diffracted waves are derived from the uniformly valid asymptotic expression for diffraction of point-source-generated waves by a semi-infinite right-angled rigid wedge. The agreement of the theoretically calculated SPL in the farfield with those measured values gives a substantial verification of the applicability of the geometrical theory of diffraction to the experimental example of a 130-cm × 76-cm × 152-cm water-filled steel tank excited at 265 Hz by two underwater speakers within the tank.
Ultrasonic absorption measurements in mammalian tissues
Authors: Goss S. A. , Frizzell L. A. , Dunn F.
Published: October 2005

The ultrasonic absorption coefficient has been determined by the transient thermoelectric technique as a function of frequency in the range 0.5–7 MHz, for a number of mammalian tissues and organs. Results indicate that (1) appreciable differences may exist between the coefficients of absorption and attenuation, (2) absorption coefficients of widely varying tissue types and species differ from one another less than do the corresponding attenuation coefficients, and (3) the frequency dependencies of absorption and attenuation are similar. The possible relationship between absorption and attenuation processes which occur in biological tissue is examined in light of these results.
Loudness scaling by means of loudness-ratio judgments
Authors: Levitt Harry
Published: October 2005

Judgments of comparative loudness (e.g., loudness-ratio judgments or judgments of loudness relative to a reference sound) show a high degree of repeatability and loudness scales developed from such judgments have been found to be reasonably similar for different subjects. These scales, however, have typically been derived from a limited subset of a much larger matrix of comparative judgments. The scaling of loudness by the method of loudness doubling, for example, concentrates observations on only one side and close to the diagonal in the matrix of possible loudness-ratio judgments. A loudness scale obtained solely by the method of loudness doubling differs systematically from that obtained by loudness halving, and both scales differ from that obtained by loudness quadrupling. Thus, although the judgments are reasonably repeatable, the exact form of the loudness scale depends on which subset of judgments is used. In this paper, a general approach to loudness scaling based on a complete matrix of loudness-ratio judgments is developed and the results obtained from three separate implementations of the approach are discussed.
Discrimination of subphonemic phonetic distinctions
Authors: Donald S. L.
Published: October 2005

Seven native speakers of Thai and seven native speakers of English took part in a set of discrimination experiments. The Thai-speaking subjects took part in discrimination tests of both labial and velar stimuli which varied along voice onset time continua. The English-speaking subjects took part only in the velar discrimination test. The Thai language makes phonemic distinctions between voiced and voiceless unaspirated stops at the labial and dental places of articulation. However, Thai does not make a distinction between voiced and voiceless unaspirated velars. English does not make this distinction at any place of articulation. Therefore, the Thai velar discrimination functions can be compared both with discrimination functions in which a phonemic distinction is made between voiced and voiceless unaspirated stimuli and also with the English-speaking subjects' discrimination functions where no such phonemic distinction exists in the language. The English-speaking subjects' discrimination functions are characterized by a single peak spanning the phoneme boundary. The Thai-speaking subjects' labial discrimination functions are characterized by a large peak spanning each phoneme boundary. Their velar discrimination functions are characterized by a large peak spanning the phoneme boundary and a smaller peak spanning the subphonemic but systematically relevant phonetic boundary.
Forward masking, pulsation threshold, and lateral suppression: An overview
Authors: Houtgast T.
Published: October 2005

Traditionally, auditory spectral resolution is studied psychophysically by masking experiments (i.e., the effect of a masking stimulus on the detection threshold of a test tone with variable frequency). During the last decade there has been increasing experimental evidence of an essential qualitative difference between the results of two classes of such experiments: (a) masking stimulus and test tone being presented simultaneously (direct masking) or (b) nonsimultaneously (forward masking, pulsation threshold). This difference can be interpreted as an effect of lateral suppression (spectral sharpening) which manifests itself only in case of nonsimultaneous presentation of masking stimulus and test tone. An overview of the relevant data is presented (e.g., auditory Mach bands, two-tone suppression, increased ripple resolution, etc.), with occasional references to related electrophysiological data. The experimental data lead to the notion of a peripheral stage of spectral sharpening of such a nature that it does not affect the detection threshold of a test tone in direct masking.
Relative velocity exponents for jet engine exhaust noise
Authors: Stone James R.
Published: October 2005

The effect of flight on jet engine exhaust noise has often been presented in terms of a relative velocity exponent n as a function of radiation angle. Prediction methods (e.g., Bushell, 1975) have also been proposed on this basis. The value of n is given by the OASPL reduction due to relative velocity divided by ten times the logarithm of the ratio of relative jet velocity to absolute jet velocity. In such terms, classical jet noise theory (Ffowes Williams, 1963) would predict a value of n = 7 at 90° to the jet axis with n decreasing as the inlet axis is approached and increasing as the jet axis is approached. However, flight tests have shown a wide range of results, including negative values of n in some cases. It is shown in this paper that the exponent n is positive for pure jet mixing noise and varies, in a predictable manner, as a function of jet conditions and flight velocity. It is also shown that when the effects of shock noise and internally generated noise are considered the range of n values predicted is increased, and in some cases negative values of n are predicted. These calculations are based on simple empirical models for jet mixing noise, shock noise and internally generated noise.
Acoustic power spectra due to multiple internal wave scattering
Authors: Tappert F. D. , Dozier L. B.
Published: October 2005

We have previously developed a statistical theory, based on a normal mode representation of the acoustic pressure field, which describes the multiple-scatter effects of internal wave fluctuations [J. Acoust. Soc. Am. 63, 353 (1978)]. This theory has been extended to include quasistatic time-dependent effects as are needed to predict the temporal coherence and power spectra of cw acoustic signals. In terms of the random normal mode amplitudes an(r,t), we have derived a generalized master equation for the second-order statistics 〈an(r,t)an*(r, t + τ)〉. We then form 〈p(r,z,t)p*(r, z, t + τ)〉 by incoherently summing modes, and Fourier transform with respect to τ to obtain acoustic power spectra as functions of range and depth. We find that in the saturation (equipartition) regime, the rms bandwidth continues to increase proportional to √r. Numerical examples of power spectra will be presented. [Work supported by ONR.]
Ocean surface duct propagation. II. A simple accurate model for surface duct propagation loss
Authors: Woodsum Harvey C.
Published: October 2005

A simple accurate model has been devised for ocean surface duct propagation. The model assumes the following form for the propagation loss: P.L. = 60 + 10 logrT + 10 logr − “gain,” where the transition range from spherical to cylindrical spreading, rT, is computed from the limiting ray for the duct, and the “gain” term is computed using the normal modes of the duct, as a ratio of the coherent mode sum to the incoherent sum. Complex reflection coefficients at the “turning points” for each mode determine the leakage of energy out of the duct due to diffraction and scattering; the (real/imaginary) parts of these reflection coefficients determine the (imaginary/real) parts of the normal mode eigenvalues. Absorption losses are added in an ad hoc fashion for each mode. This model is shown to be equivalent in an approximate way to the complete Green's function solution to the wave equation which includes both the discrete and continuous portions of the eigenvalue spectrum.