bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity of vestibular nerve fibers to audio-frequency sound and head vibration in the squirrel monkey
Authors: Young Eric D. , Fernández César , Goldberg Jay M.
Published: October 2005

The sacculus has been shown to act as a hearing organ in some fish and amphibians. In mammals, it is known to be sensitive to static gravitational forces, but its sensitivity to sound and vibration is unknown. We have studied single fibers in the vestibular nerve of squirrel monkeys to determine the responsiveness of the sacculus and the other vestibular end organs to air-conducted sound and head vibration. The fibers responded to intense sounds (above 90 dB SPL) and head vibration (above 0.0001 g) at frequencies between 0.1 and 1.0 kHz. Responses consisted of both phase locking and changes in discharge rate. The responses were broadly tuned with maximum sensitivity around 150 to 350 Hz. Fibers with irregular spontaneous discharge tended to be more sensitive than regular fibers. Otolith fibers encountered in the same punctures as posterior canal afferents were presumed to be from the sacculus; they were not more sensitive than other vestibular afferents.
Interaction between mechanical and electrical stimuli in hair cell systems
Authors: Strelioff D. , Honrubia V.
Published: October 2005

In order to determine the effects of electrical potentials upon mechanically evoked responses of hair cell systems, the neural activity of single afferent fibers innervating the lateral line organ of the African clawed toad Xenopus laevis was recorded during stimulation with combinations of sinusoidal mechanical and electrical stimuli. It was found that a 2-Hz electrical stimulus modulated the amplitude of the response evoked by a 32-Hz mechanical stimulus by the same proportion that it modulates the spontaneous activity in the absence of mechanical stimuli. It was also found that responses to a 32-Hz electrical stimulus could be modulated by a 2-Hz mechanical stimulus. These results demonstrate that the gain of this hair cell system for one type of stimulus is determined by the instantaneous magnitude of the other stimulus. Similar interactions between mechanical stimuli and potentials generated by adjacent hair cells probably occur in other hair cell systems and may play an important role in signal processing. [Supported by grants from the Deafness Research Foundation and NINDS.]
Absolute measurements of acoustic emission
Authors: Hatano Hajime
Published: October 2005

The present paper summarizes and reviews the current understanding of the absolute measurements of the amount, frequency spectra, and wave forms of the elastic energy which is rapidly released during acoustic emission events. Quantitative emission measurements are essential both for basic research and for practical applications, but many problems are left to be resolved. In general, the absolute measurement involves two fundamental problems: the absolute calibration of the transducer and the estimation of the transmission characteristics of the propagation path from the source to the transducer. For the first problem, the reciprocity technique can be employed, when the wave mode of the acoustic emission signals is identical to what is employed in the calibration. The second is a problem of greater difficulty. A few attempts have been made only under comparatively simple conditions. In practice, the wide frequency distribution and low energy levels of most acoustic emission signals complicate the measurement by the conventional transducers. Recent studies on the calibration of the transducers and the absolute measurements during materials testing will be discussed. [Work supported in part by ONR.]
Acoustic emission due to deformation and fracture
Authors: Ono Kanji
Published: October 2005

This paper reviews diverse observations of acoustic emission from materials and attempt to interpret them on the basis of current knowledge of plastic deformation and fracture. An attempt is made to unify diverse and often conflicting findings on the basis of dislocation dynamics of glide and twinning. Observed acoustic emission characteristics have been classified into five categories, which arise from heterogeneous and homogeneous yielding, dynamic strain aging, twinning, and other heterogeneous deformation and strain-induced transformation during plastic deformation. It is shown that the micro-yielding concept with suitable modifications best explains various acoustic emission behavior observed. Fracture processes generally produce high levels of acoustic emission, except for fracture in low-strength ductile materials. Various fracture mechanisms found in different classes of materials are correlated to observed acoustic emission behavior. Relationships between threshold crossing counts and stress intensity factor or crack tip opening displacement are discussed. It is shown that the consideration of amplitude distribution effects can substantially alter such relationships and simple analyses previously reported by others will lead to an erroneous conclusion. More elaborate analyses of acoustic emission from fracture processes are presented that suggest the possibility of identifying the mechanisms of acoustic emission. [Work supported by ONR.]
Recent advances in understanding of acoustic emission from fiber composites and metals
Authors: Hamstad M. A. , Tatro C. A.
Published: October 2005

The time and frequency domains of acoustic emission signals generated during loading of Kevlar 49/epoxy composites have been studied. The effects of composite thickness, transducer type, and load level have been examined. Results indicate that relatively low frequencies predominate. A study of the frequency spectrum of acoustic emission signals generated during fatigue testing of fracture toughness specimens has been completed. In particular, the dependence of frequency on the stress intensity level was studied. Extensive tension and compression testing of unflawed 7075 and 2124 aluminum has been undertaken. Among the results are (i) a correlation between fracture toughness and the acoustic emission generated during a compression test of 2124-T851; (ii) the rate of acoustic emission energy sensed at strains greater than 1.5% is more than two orders of magnitude greater in tension than in compression; and (iii) acoustic emission can easily be used to sort out plates of 7075 aluminum which have undesired 20–60-μm inclusion particles. [This work was performed under the auspices of the U.S. Energy Research and Development Administration, under contract No. W-7405-Eng-48.]
Nondestructive testing of pressure containment system using acoustic emission analysis
Authors: Parry Dwight L.
Published: October 2005

The nondestructive testing technology of acoustic emission analysis is an effective tool for the integrity analysis of pressure-containment systems. Hundreds of tests conducted in the petrochemical and nuclear industries have established the technology as a tool which allows complex and/or relatively inaccessible pressure-containment systems to be evaluated for structural integrity in a fast, efficient manner. Its application in the petrochemical industry for multiple structure evaluation is producing significant cost savings. Its application for the integrity analysis of nuclear-plant pressure-containment systems is reducing personnel radiation exposures and providing more complete system integrity assurance. Typical test descriptions present the test procedures used and the results derived in use of the technology.
Computer-aided acoustical simulation of pathological knee joints. I. in vitro
Authors: Zavodney L. D. , Chu M. L.
Published: October 2005

Previous studies have shown that different pathological knee joints produce unique acoustical characteristics. In-vitro simulation of acoustical signature was attempted using bovine knee joints placed in a “flexing” machine. Mechanical destruction was induced on the articular cartilage surface, and the noise produced during rubbing was picked up by a sensitive condenser microphone, amplified, recorded, and converted into digital form. A computer program was written to perform various statistical analysis. Cartilage surface roughness was measured with a profilometer and a spatial waveform roughness distribution curve was plotted out. Preliminary results show that the unique acoustical characteristics of the various knee-joint diseases can be simulated fairly well with this technique. This study therefore provides a rough diagnostic indication of the degree of roughness of the various types of knee-joint diseases. [Work supported by NIH.]
Computer-aided acoustical simulation of pathological knee joints. II in vivo
Authors: Chu M. L. , Mostardi R. A. , Gradisar I. V. , Zavodney L. A.
Published: October 2005

Suitable models of pathological knee-joint diseases were created on rabbits using biological-surgical techniques. At regular intervals during the progress of the disease, acoustical signatures were retrieved during flexion and extension of the knee joints. The noise was recorded on tape and digitized using an A/D converter. With the use of an IBM computer various statistical analysis were performed. The rabbits were sacrificed at regular intervals during the experiment and the roughness measured with a profilometer. The spatial waveform was recorded and statistically analyzed. Preliminary results showed that close correlation exists between the degree of roughness of the “diseased” cartilage and the acoustical signature emitted. This study verifies the strong correlation between the knee-joint cartilage pathological condition and the acoustical noise emitted during extension and flexion. [Work supported by NIH.]
Effects of masker intensity on the bandwidth of the auditory filter
Authors: Weber Daniel L.
Published: October 2005

The threshold of a pulsed sinusoid centered in a notched-noise masker was measured as a function of the bandwidth of the notch. Assuming that the amount of masking reflects the amount of noise passing through an auditory filter centered on the signal frequency, the derivative of a curve fitted to the data is an estimate of the auditory filter shape [R. D. Patterson, “Auditory filter shape,” J. Acoust. Soc. Am. 55, 802–809 (1974)]. Estimated of the bandwidth of the auditory filter, defined as the half-power bandwidth, were found for three frequencies (1000, 2000, and 4000 Hz) and five noise spectrum levels (10, 20, 30, 40, and 50 dB). The bandwidth of the auditory filter increases with masker intensity above 30-dB noise spectrum level. At these higher intensities, an interaction with signal frequency is also observed, the bandwidth being relatively greater at higher frequencies. [This research was supported by the NIH.]
On temporal masking by a synthetic vowel on a consonant-like burst
Authors: Revoile S. , Wilson M. P. , Pickett J. M.
Published: October 2005

Previously, we found masking by a remote portion of vowels on discrimination of a transition in the second formant, particularly at sound levels required by listeners with severe hearing loss. Would such masking also extend from a vowel to the noise-burst cue of a consonant? We measured threshold shifts for the detection of a brief high-frequency noise burst that preceded or followed a two-formant synthetic vowel. The listeners had normal hearing or long-term, moderate-to-severe sensorineural hearing losses. Threshold shift was the difference between the burst threshold for the noise burst alone and threshold when the burst was preceded or followed by the vowel. The vowel level was at the MCL of each listener and also at 95 and 105 dB for the normal-hearing listeners. For both groups of listeners there was little or no threshold shift of the noise burst when the vowel was heard at MCL. For the normal-hearing listeners, greater masking of the noise burst occurred when the vowel was presented at 95 and 105 dB, particularly when the noise burst followed the vowel.
What is the nature of stress in English nominal compounds?
Authors: Goldstein Ursula G.
Published: October 2005

Traditional theories of phonology maintain that nominal compounds have a [1/3] stress pattern whereas nominal phrases are characterized by [2/1] stress [N. Chomsky and M. Halle, The Sound Pattern of English (Harper and Row, New York, 1968)]. However, there does not appear to be a sharp boundary between compounds and noun phrases, either in speaker's strategies for indicating stress, or in their perception of it. Indeed, there appears to be a continuum, where certain word pairs like “apple core” are definitely perceived and produced as compounds, others such as “boiling water” are usually noun phrases, and numerous others like “parcel post” or “box lunch” can be either. Durational and fundamental frequency data will be presented for three naive subjects who recorded 40 word pairs in sentence context. Additional subjects were given a written list of these sentences with the word pairs underlined and asked to circle the one syllable of each pair that should be most stressed. Certain classes of word pairs received more consistent stress assignments than others, but definite rules predicting stress seem to be difficult to formulate.
Perceived stress as a function of the fundamental frequency contour
Authors: Campbell Hugo W.
Published: October 2005

The perceptual effects of variations in the fundamental frequency contour were studies in some detail in identification of a disyllabic word as a noun or a verb. The F0 contour of the first syllable had one of three slope values but had the same average frequency. Within the second syllable, both the slope (four values) and the average frequency (at least eight values) were varied. The verb “subject” was taken from a naturally spoken sentence which was analyzed and resynthesized with modified pitch contours by use of the LPC technique. Results show that the shift in categorization is relatively gradual with respect to small gradual changes (step size of 2 Hz) in average F0. The boundary is dependent on the slope of both the first and the second syllable. These identification characteristics will be discussed in relation with the previously reported results of discrimination characteristics [H. W. Campbell, J. Acoust. Soc. Am. 58, S57(A), S92(A) (1975)].
Scaling rules for organ flue pipe ranks and for the string choirs of harpsichords
Authors: Fletcher N. H.
Published: October 2005

The criteria for design of an organ flue pipe rank, properly balanced and coherent in power and harmonic development, are discussed in terms of present understanding of the sound production process. A scaling with pipe diameter D proportional to ν1−x, where ν1 is pipe fundamental frequency and x = 0.83, is found to give approximately constant harmonic development across the rank but too much loudness in the bass. The traditional scaling rule with x = 0.75 nearly equalizes the loudness and increases harmonic development towards the bass of the rank. Similar criteria applied to the string choirs of harpsichords, in which decay time must be considered as well, lead to scaling rules which increase wire diameter and move the plucking point progressively towards the end of the string in the bass. The relations between the two types of scaling rule are discussed.
Influence of relational context on pitch recognition as a function of retention interval
Authors: Deutsch Diana
Published: October 2005

Subjects made delayed pitch comparisons when the tones to be compared were separated by a retention interval during which six extra tones were interpolated. All tones were 300 msec in duration. The pause between the last interpolated tone and the comparison tone was either 500 or 2000 msec; otherwise all pauses were 500 msec. The standard and comparison tones were accompanied by tones of lower pitch which the subjects were instructed to ignore. In some conditions the harmonic intervals formed by the standard and comparison combinations were identical and in others they differed. It was found that when the standard and comparison tones differed but the standard and comparison combinations formed identical harmonic intervals, there resulted a substantial increase in errors of misrecognition. However, this occurred only with the longer delay between the standard and comparison tones and not with the shorter delay. It appears that during the extra delay pitch information decayed rapidly, resulting in judgments based on harmonic interval rather than pitch.
Periodicity analysis: Short term or long term?
Authors: Pollack Irwin
Published: October 2005

The exact repetition of a random auditory pattern results in a periodic signal. The strength of the resulting periodicity can be reduced by embedding random elements within the otherwise periodic pattern. Periodicity thresholds were obtained by finding the proportion of randomly embedded elements required by listeners to achieve a fixed discrimination level between repeated and nonrepeated patterns. If the location of the repeated elements within the pattern does not change from one repetition to the next, we have the condition appropriate either for a short-term, or for a long-term, periodicity analysis. If, however, the location of the repeated elements changes between successive repetitions, we have the condition appropriate for a short-term analysis, since a long-term periodicity analysis would reveal a nonperiodic signal. Periodicity thresholds are nearly equal under the two conditions; thereby suggesting a short-term periodicity analysis by the auditory system.
Fission in the perception of tone sequencies produced by level difference
Authors: van Noorden Leon
Published: October 2005

The prolonged alternation of two pure tones ABAB .. can be ambiguous with respect to perception. Depending partly upon tone rate and frequency interval the observer may hear the string ABAB .. (temporary coherence) or the two strings A A . and B B . (fission). The present experiment deals with the question whether an amplitude difference (ΔL) between A and B instead of a frequency difference (Δf) can give rise to the same fission effect. With an adjustment measurement it has been determined that at moderate tone rates (2–10 tones/sec, tone duration 40 msec) the minimum level difference for fission is about 3 dB. At faster tone sequences a new effect has been observed (roll effect). Here the string of soft tones cannot be heard separately; instead, the soft tones seem to occur at twice their presented rate. The existence region of this effect in the ΔL-Δf plane can be related to the pulsation threshold, perhaps an indication of the more peripheral origin of this effect. [Work suppoted by Netherlands Organization for the Advancement of Pure Scientific Research.]
Is periodicity detection central?
Authors: Huggins A. W. F.
Published: October 2005

What periodicity is perceived when two different segments of random noise, A and B, are alternated dichotically between the ears (i.e., left: ABABA ..; right: BABAB ..)?. Earlier work has suggested preliminary auditory processing is performed before signals in the two ears are combined [J. Acoust. Soc. Am. 56, 939 (1974)]. If so, the perceived period should correspond to the length of the segment that iterates in one ear, AB. But if periodicity is central, the perceived period should be equal to the length of the alternated segments, since each segment in one ear is immediately repeated in the other. Subjects compared an alternated sequence with two dichotic anchors (left: CCC …; right: DDD ..), for segment durations between 25 and 400 msec. One anchor had a period equal to the alternated segments (i.e., C=D=A=B), and the other had twice the period (i.e., C=D=2A=A+B). The results show that periodicity is not central at the shorter durations, but becomes so when segments are longer than 140–200 msec. [Research supported by NIH Grant NS04332.]
Perception of monotic and dichotic harmonic musical intervals
Authors: Burns E. M. , Ward W. D.
Published: October 2005

A number of authors have made the assertion that musicians are unable to recognize harmonic intervals or chords when the component tones are presented dichotically and have cited experimental results to support this view. The results of a number of other experiments reported in the literature, however, contradict this assertion. In an attempt to clarify this issue, several highly trained musicians were tested in a forced-choice harmonic-musical-interval recognition paradigm. The component tones of the intervals were sinusoids and were presented either monotically or dichotically. The observers were able to recognize the dichotic intervals. In fact, for the condition of small intervals at low absolute frequencies, the observers achieved higher recognition performance in the dichotic mode than in the monotic mode. A more interesting result is that, for this situation, the observers obtained higher recognition performance for both monotic and dichotic presentation than would be predicted from the results of previous experiments in monotic and dichotic pitch fusion.
Perception of dichotic chords by split-brain subjects
Authors: Efron R. , Bogen J. E. , Yund E. W.
Published: October 2005

An ear dominance for pitch information has been described for dichotic chords [R. Efron and E. W. Yund, Neuropsychologia 12, 249–256 (1974); 13, 137–150 (1975); 13, 151–161 (1975); Brain and Lang. 2 (1976) (in press)]. This work has shown that a subject's ear dominance for pitch has no correlation with his ear dominance for dichotic consonant-vowel (CV) syllables or his handedness. In addition, the ear dominance is unaffected by attempts to attend to one or the other ear and the subject's performance is characterized by unusually low variance. This array of characteristics suggests that the asymmetry is introduced at subcortical levels. Ear dominance for the pitch of dichotic chords in split-brain subjects was determined using a verbal response (testing the left hemisphere), a right-hand response (testing the left hemisphere), and a left-hand response (testing the right hemisphere). The psychometric curves in each subject were identical for the three modes of report indicating that each hemisphere displays the same ear dominance, i.e., if a subject was right-(or left-) ear dominant for dichotic chords both hemispheres were equally so. On the other hand, all the split-brain subjects had an overwhelming right-ear dominance for dichotic CV's , as previously described [B. Milner, L. Taylor, and R. W. Sperry, Science 161, 184–186 (1969). These results suggest that the same imbalance of pitch information is received by both hemispheres as a result of an asymmetry in a subcortical central pitch processor.
Ear dominance and intensity independence of dichotic chords
Authors: Yund E. W. , Efron R.
Published: October 2005

Recent papers [Efron and Yund, Neuropsychologia 12, 249–256 (1974); Yund and Efron, Perception Psychophys. 15, 383–390 (1974); Deutsch, Nature 251, 307–309 (1974); J. Acoust. Soc. Am. 55, S18(A) (1974); Yund and Efron, Neuropsychologia 13, 137–150 (1975); Efron and Yund, Neuropsychologia 13, 151–161 (1975); House, J. Acoust. Soc. Am. 58, S54(A) (1975)] have called attention to an ear dominance in the perception of dichotic chords. The primary observation common to these studies is the report of a difference in the pitch mixture of two dichotic chords in which the ear-frequency relationship is reserved. For some subjects the mixture is dominated by the frequency of the tone to the right ear; for others by the left-ear tone; for still others the pitch mixture is unchanged by the ear-frequency relationship. When this ear dominance is coupled with a lateralization effect, an auditory illusion results. Efron and Yund (1974) produced lateralization by interaural intensity differences. In the Deutsch and House experiments lateralization of the chord is in the direction of the ear receiving the higher frequency tone. In addition to the phenomenon of ear dominance which determined the dichotic pitch mixture, Yund and Efron (1975) also reported that this pitch mixture is independent of interaural intensity differences over a surprisingly large range.
Upper frequency limit of periodicity pitch perception in cat
Authors: Chung David Y. , Colavita Francis B.
Published: October 2005

We have established a procedure for behavioral assessment of periodicity pitch perception in the cat. Basically, the procedure involves training animals to make a differential response to different pure tones, and then testing for response transfer when complex stimuli known to produce periodicity pitch sensations in humans are substituted for the pure tones. Stimuli consisted of three to five harmonically related frequencies of the same amplitude and phase. Appropriate controls are run to insure that extraneous variables such as intensity cues or rapid new learning are not contributing to response transfer in the test situation. This behavioral procedure has recently been used to measure the upper frequency limit of periodicity pitch in the cat. The frequencies tested were 100, 200,300, 400, 600, 800, 900, and 1200 Hz. The data indicate that the upper frequency limit of periodicity pitch in the cat is on the order of 600 to 800 Hz. It also appears that periodicity pitch can still be perceived when the center frequencies of the complexes used to generate periodicity pitch are as high as 4000 to 5000 Hz. The data are in approximate accord with results in the literature obtained from human observers. [Work supported by NINCDS Grant NS09027.]
Frequency-difference thresholds in Chinchilla using conditioned avoidance techniques
Authors: Nelson D. A. , Keister T. E.
Published: October 2005

Chinchillas were trained to discriminate or detect pure-tone frequency differences using shock-avoidance procedures. Two psycho-physical paradigms were investigated. Initial attempts at determining frequency-difference thresholds utilized a complex discrimination paradigm. Although discriminations of large frequency differences were obtained from Chinchilla with adequate success, discriminations of very small frequency differences could not be trained. Therefore, determinations of frequency-difference thresholds were not possible with this complex discrimination paradigm. A second relatively simple detection paradigm, involving the detection of frequency alternation in an on-going train of tone bursts, proved to be a somewhat more successful technique. Frequency alternation detection was quickly learned by the Chinchillas and frequency-difference thresholds were obtained with an adaptive sequential procedure. Those frequency-difference thresholds are comparable to frequency-difference thresholds obtained in other animal species by previous investigators. Some of the difficulties in maintaining reliable behavior in Chinchillas with shock avoidance techniques are discussed. [Work supported by DRF grant.]
Speech perception by normals in four conditions of filtering
Authors: Danhauer J. L. , Lawarre R. M. , Reisman K.
Published: October 2005

One hundred and twenty normally hearing adults listened to sixteen consonants in a phrase context and made similarity ratings for 256 diadic pairs on a 9-point equal-appearing interval scale. Stimuli were presented at MCL via three conditions of low-pass filtering and one nonfiltered. Subjects' ratings were converted to 16 × 16 full-symmetric dissimilarity matrices and submitted to INDSCAL analyses. Results revealed common perceptual features for all groups including sibilancy, stop/continuancy, front/back place, and voicing; however, these were not always clearly distinctive for each group. Group-specific features strongly present included sibilancy, stop/continuancy, and place for nonfiltered; plosive and place for 4000-Hz low-pass; stop/continuancy and place for 2000-Hz low-pass; and voicing and stop/continuancy for 500 Hz. Also, features showing interaction among manner, place, and voicing categories were noted for each group. Findings were compared to and found to agree with earlier results for hearing impaired subjects having sensorineural losses compatible with the present frequency cutoffs.
The perceptual importance of the second formant during rapid spectrum changes
Authors: Klatt Dennis H. , Shattuck-Hufnagel Stefanie R.
Published: October 2005

Brief stimuli incorporating rising and/or falling rapid spectrum changes were presented to listeners for judgments of relative similarity. Stimuli were composed of 2 pure-tone glissandos which were both rising in frequency, both falling, diverging, or converging. Similarity judgments among random triads of these stimuli could either be based on the identity of the lower-frequency component, the higher-frequency component, or mirror-image symmetry. Systematic study of many possible combinations of component frequencies and relative amplitudes indicates that the component in the frequency region of the second formant determines the response when competing with higher frequency glissando components. The results cannot be explained by conventional masking, loudness, frequency discrimination, or differences in pitch between rising and falling glissandos. We conclude that there exist detectors of frequency change within the central nervous system. Further experiments suggest that these rapid spectrum change detectors have a uniform distribution up to about 1500 Hz and fall off gradually in number above this frequency. The detectors are broadly tuned and seem to be located in a nucleus receiving inputs from only one ear. [This research was supported by an NIH grant.]
Context sensitive rules for speech synthesis
Authors: Carlson R. , Granström B.
Published: October 2005

The combination of context sensitive rules with feature specification of segments has proved to be very efficient in formulating grammars in general, and the phonological component in particular. Through expansion of the notation generally used in generative phonology to include numerical functions and continuous variables it is possible to include the phonetic (i.e., output) component as well. A programming language with these properties has been implemented. One application has been a text-to-speech system for Swedish written entirely in this language and hence easily open to modification. The system is presently run on an interactive minicomputer with disk storage. To enhance the interactiveness of the system, rules have been allowed to include external user-controlled variables. Rule application is automatically counted to facilitate an evaluation of rule productivity.
Hard-wired real-time LPC synthesizer
Authors: Olive J. P.
Published: October 2005

A hard-wired real-time linear predictive coding (LPC) synthesizer has been built. The synthesizer computes the speech signal from data which it receives pitch synchronously from a computer: the data includes a pitch period, sum of squares amplitude, and 12 LPC coefficients. In computing the speech signal for one pitch period, the overhang energy from previous pitch periods contributes to the energy of the signal; this factor must be taken into account in order to eliminate roughness in the resultant speech. The device computes a scaling factor for the excitation function which allows for this overhang energy. This requires substantial additional computation; therefore, fast arithmetic processors were designed so that speech can be synthesized in real time. All computation is performed in floating-point arithmetic to eliminate round-off errors. The resulting device can synthesize speech in real time, and the speech quality is the same as that of the software version.11
Perceptual correlates of affection reaction to processed speech
Authors: Voiers W. D. , Sharpley A. D. , Lake O. L.
Published: October 2005

A specially prepared semantic differential rating form was used to compare the perceptual and affective reactions of two groups of listeners to speech processed by a representative selection of digital voice communication systems. One group consisted of professional laboratory subjects. The other was composed of military personnel who were routinely involved in military communications. Factor analysis was used to identify the perceptual correlates of the acceptance or affective reactions of the two groups to the various systems. Five orthogonal factors accounted for the systematic component of rating variance in both cases. Although the two groups discriminated with respect to the same perceptual parameters, they valued certain of these parameters differently when rating the systems from the standpoint of acceptability. This finding provided the basis for the development of a practical method of predicting the operational acceptability of communication systems from the responses of laboratory subjects who may not share the operational population's valuation of the various perceptual parameters. It is necessary only that the two groups share the capacity to discriminate systems with respect to these parameters. [Work supported in part by the Defense Communications Agency.]
Do mothers maximize phonetic contrastivity: a study of VOT
Authors: Baran J. A. , Zlatin M. A. , Daniloff R. G.
Published: October 2005

Voice-onset-time (VOT) measurements were obtained from the productions of three adult females under the following conditions: (1) adult-directed conversation; (2) child-directed conversation; and (3) recitation of citation forms. VOT values were derived directly from frequency-by-time wide-band spectrograms by three independent judges. Results indicate adequate reliability to within 5 msec was obtained among the judges on all spectrograms. Significant differences were noted among and within the three conditions. These results are discussed in terms of current theories concerning parental roles in the infant's acquisition of language.
Features of infant sounds: the emergence of cooing
Authors: Stark Rachel E.
Published: October 2005

There is said to be a discontinuity in development of vocalization at the time when comfort sounds (cooing) first emerge. In the present study, vocalizations produced by two normal female infants before and after the emergence of comfort sounds were studied. The vocalizations were first classified as cry, discomfort, vegetative (coughing, burping), and, from 6 to 8 weeks of age onwards, comfort sounds. Examples from each class were selected randomly for auditory and spectrographic analysis. The features of voicing, breath direction, and vowel-like vs consonant-like were documented. The two infants differed little from one another with respect to these features. Cry and discomfort sounds were both predominantly vowel-like, voiced and egressive. Vegetative sounds were predominantly consonant-like, voiceless and ingressive. The features voiced and egressive were incorporated with the feature consonant-like in comfort sounds. Thus, the apparent discontinuity between the earlier sound classes and the later-appearing comfort sounds may derive from the fact that a new combination of features is formed in comfort sound, each feature deriving from a previously existing sound class. This new combination coincides with emergence of the ability to express pleasure. [Work supported by NINDS.]
Speech production in two-three-year old children: a perceptual analysis of selected segmental features
Authors: Kressin L. Y. , Marquardt T. P. , Asp C. W.
Published: October 2005

The ability of two-three-year old children to produce disyllables was investigated. Eighteen children with normal language skills were divided into three age groups: 24–27 months, 28–31 months, and 31–35 months. Each was presented twenty disyllables three times with either rising or falling intonation. The disyllables consisted of reduplicated CVC syllables which varied from the initial to the final consonant of each syllable in place, voicing, or manner. Analysis of the imitations of each of the stimuli by the subjects revealed that regardless of intonation pattern: (1) production of phonemes within the environments of back to front, voiced to voiceless, and oral to nasal was significantly better than within the environmental counterparts of front to back, voiceless to voiced, and nasal to oral; (2) phonemes in the second syllable were produced correctly significantly more often than phonemes in the first syllable in environments varying in place or voicing but not manner; (3) fewer errors in production of the phonemes as a function of age were noted.
Distinctive feature analysis of choice reaction times of consonantal similarity judged by children of different age groups
Authors: Stewart James M. , Singh Sedanand
Published: October 2005

Choice reaction time (CRT) was used as criterion to determine strategies in judging similarity of consonants. Subject comprised thirty children of 5, 6, and 7 years with five males and females in each age group. The ensemble of English phonemes were /k, f, v, θ, ∂, s, z, ∫, e,j, w, r/ each followed by /a/. The overall CRT for 5- and 6-year olds were not different; however, they were different for the 7-year olds. The CRT for females were different from the males. A distinctive feature analysis revealed that a greater CRT was found for minimally distinct pair than any other pair. No difference was found among the CRT's associated with pairs different by two-five features. It was concluded that these children utilize distinctive features in making perceptral judgments by availing themselves with the knowledge of the redundancy aspect of the differences. The INDSCAL analysis revealed that the utilization of features and their weightings by the three age groups showed no systematic differences. The perceptual features obtained from these children's judgments had both similarities and differences of features manifested in earlier studies on adults.
Computer processing of “tips of the slongue”
Authors: Fromkin V. A. , Silva G. , Galloway L.
Published: October 2005

The “UCLA corpus” of speech errors is now being analyzed by a computer program. The program analyzes the target (intended) utterance and the corresponding actual utterance and finds the differences between them. Both utterances are analyzed in terms of phonemes, distinctive features, syntactic categories, and constituents, word, morpheme, and syllable positions, stress, and phonological environment. A determination of the maximum “distance” between the influencing or contaminating element and the error provides information on the size and structure of the string which is stored prior to articulation. Confusion matrices for target and actual phonemes and features will be presented. The paper will also report on the percentage of errors resulting in actual words, the frequency of errors of perseveration, anticipation, and transposition, the stress values of the syllables involved, the effect of similar phonetic contexts, and the hierarchy of syntactic categories of words involved in errors. These data provide information regarding the mechanisms involved in both error-free and deviant utterances. [Research supported by USPHS Grant No. NS 12303-01.]
Acoustic sensing of large-scale ocean dynamic processes
Authors: Clark J. G.
Published: October 2005

In recent years relationships have been established between fixed-system acoustic transmission fluctuation and ocean dynamic processes on space scales of tens and hundreds of kilometers. In this context, tide-driven processes have been studied in some detail, transport-related variations in the dynamic structure of the Gulf Stream have been studied, and investigations in progress include preliminary attempts to relate acoustic phase fluctuations on the time scale of several months to Rossby waves and/or deep-ocean eddies. These results will be reviewed, and the most recent deep-ocean experimental conclusions compared with MODE and IWEX findings. The viewpoint taken throughout is that environmental information is being extracted from a “noise background” in the sound-speed field a major component of which is the internal wave continuum. Measurement problems due to multipath effects will be discussed.
Observations of oceanic fine structure
Authors: Kaye G. T.
Published: October 2005

SCAR, an acronym for SCattering ARray, is a large-aperture planar hydrophone array with sound source that has been used to observe the backscattering of sound by fine structure in the oceanic water column in the frequency range of 3.5–20 kHz. The signals are clipped and 1024 samples of phase for each of 128 hydrophone channels are recorded. Time delays and phase shifts for each range step are computed for two modes: returns due to specular reflection from density layering and returns due to point scatterers in the water column. Beamforming of the data provide a side-by-side display of the two outputs. Distinct differences between modes and between the amplitude information output of the signal before clipping can be noted. The depth distribution of the density layering correlates with XBT temperature profiles taken concurrently. Future signal processing will include multibeam computations, so that density layers tilted by internal wave action will still be observable. [This research is supported by the Defense Advanced Research Projects Agency.]
Aggregation arrays set up by ultrasound in biological cells
Authors: Dyer H. J. , Miller D. L. , Nyborg W. L.
Published: October 2005

Situations are discussed where ultrasound (compressional wavelength much greater than cellular dimensions) causes cytoplasm to be redistributed, forming regularly spaced clumps along a cell wall, as if set up by a mode of wall vibration. In one arrangement, the long cylindrical cells of moss protonema, Physcomitrium turbinatum, were contacted by the tip of a 78-kHz Mason horn. Here cytoplasmic mounds initially appear in a linear array with a spacing of 25 μm; with continued sonation the spacing doubles. In a second arrangement, specimens of the alga Hydrodictyon reticulatum were subjected to a 1-MHz cylindrical standing wave field using an instrument described elsewhere by D. L. Miller. In these elongated cells regularly spaced clumping is apparent after 30 min of sonication at a spatially averaged level equivalent to about 5 W/cm2 in a progressive wave. The spacings (about 70 mm for Hydrodictyon are as expected for standing waves in a membrane under tension resulting from turgor pressure. For the moss protonema we have as yet no simple model. A film will be shown. [Supported by NIH grant GM-08209.]
A comparison of phonetic and semantic sensitivity in native speakers and second-language learners
Authors: Lang Janet M. , Limber John E.
Published: October 2005

Speech signals can be described/analyzed along increasingly abstract dimensions, ranging from acoustic to syntactic to semantic concerns. For native speaker-hearers, many analyses are automatic, with in general, semantic analyses being the focal point. For individuals learning a language, many analyses seem to require a more conscious direction of attention. The probe paradigm was used to empirically compare the phonetic and semantic processing done by native English speakers and Latin Americans learning English as a second language (Lado range average to superior). In the probe paradigm, an utterance is presented to the listener. A probe word that may or may not be from the utterance follows. The listener must immediately indicate whether or not that probe was from the preceding utterance. The dependent variable is reaction time. In all cases, the reaction times of the Latins were longer than for the natives. Probes phonetically similar to a word in the utterance were always more disruptive to the Latins relative both to other kinds of probes and to the native speakers.
Effects of biomedical ultrasound on animal systems
Authors: Kaufman G. E. , Miller M. W. , Carstensen E. L.
Published: October 2005

Reports of biological effects of ultrasound at diagnostic frequencies and intensities have not been confirmed. Several investigations have failed to reproduce MacIntosh and Davies' report of chromosomal aberrations in human lymphocytes in vitro. We have been unable to reproduce Kremkau and Witcofski's report of mitotic index reduction in regenerating rat livers in vitro. At therapeutic intensities the lysis of mammalian cells in suspension is a well established effect. We have recently shown that effects short of complete cell rupture are also possible. A large fraction of the cells which remain intact is no longer viable as determined by vital dye exclusion. Future work will attempt to identify sublethal effects such as have been observed and established in plant systems. [Work supported by ERDA Contract E(11-1)3490, USPHS Grants FD00694 and GM 22680 and Fellowship No. 6F22CAO3212 from the National Cancer Institute.]
Effects of biomedical ultrasound on plant systems
Authors: Miller M. W. , Kaufman G. E. , Carstensen E. L.
Published: October 2005

Two-megahertz ultrasound at intensities from 0.5 to 20 W/cm2 for 1 min induces a wide variety of perturbations in plant room meristems; these perturbations include (1) reduced root growth rates, (2) reduced mitotic indices, (3) induced chromosomal anomalies, (4) induced cell-wall shattering, and (5) reduced protein, RNA, and DNA syntheses. Short pulses (3–100 msec) of ultrasound induced less of a biological effect than longer pulses (>100 μsec) but did not result in the elimination of an effect; the results axe consistent with the hypothesis that ultrasonic cavitation is a major mechanism for induction of biological effects. [Work supported by ERDA Contract E(11-1)3490, USPHS Grant FD00694, and Fellowship No. 6F22CAO3212 from the National Cancer Institute.]
Current status of ultrasound mammography
Authors: Baum Gilbert
Published: October 2005

Based upon the encouraging initial results achieved by ultrasound mammography with a modified high-resolution extended gray-scale ophthalmic ultrasonoscope, a completely new ultrasound mammographic system specifically designed for this purpose was constructed. This paper will describe ultrasound mammographic techniques and findings as practiced in our laboratory. The initial results achieved with this new ultrasound system will be shown. These results will be compared with previous studies on about 120 patients done in our laboratory with a modified ophthalmic ultrasound scanner. Both the range of normal ultrasonographic patterns and the ultrasonographic changes produced by various disease entities including breast cancer will be shown as well as an analysis of our results as compared to x-ray and clinical examination. [Work supported by NIH.]
Ultrasonic-intensity-insonation-duration thresholds for morphological damage to mammalian C.N.S. in vivo
Authors: Stein J. L. , Hsu W. L. , Lele P. P.
Published: October 2005

It is generally accepted that temperature elevation resulting from acoustic absorption is an important factor in insonation-induced tissue injury. The threshold temperature at which such injury occurs is found to be independent of the preinsonation base temperature of the tissue, the ambient pressure, and the insonation regime. In addition, contrary to some recently published statements, it is also found to be independent of the ultrasonic frequency. It is, however, a strong function of the duration of the temperature elevation and is thus inversely related to the duration of insonation dropping from 65°C for 0.1 sec to 44°C for 15 min in the mammalian central nervous system in vivo. In this range, the interdependence of the threshold temperature and time for tissue damage can be explained and predicted by a model based on the reaction kinetics theory. Temperature elevations to 42.5°C or lower, resulting from insonation or otherwise, do not produce any detectable morphological damage, even when prolonged for periods as long as 8 h. These observations are consistent with comparable data on other tissues, mitotic replication of mammalian cells in cell cultures, as well as with the commonly held safe upper limit for fever in man. They may thus be of considerable value in defining the safe upper limits for insonation of all but differentiating tissues. [Work supported by US PHS.]