bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent progress in computer recognition of cerebral palsy speech
Authors: Deller J. R. , Venkatesh C. G. , Hsu D. , Ferrier L. J. , Cozzens M. B.
Published: October 2005

This paper is ultimately concerned with the development of an AI communication aid for the nonverbal, profoundly motor disabled. Part of this effort is aimed at automated recognition of speech of the nonverbal. The speech study has focused on the cerebral palsied (CP) population, and recent papers have reported methodology and early experimental results concerning the lower (acoustic and word) level recognition tasks for CP speakers [Deller et al., Proceedings of the ASSP Workshop on Acoustics, New Paltz, NY (1986) and Deller et al., Proceedings of ICASSP '87, Dallas, TX (in press)]. The purpose of this paper is twofold: (1) to present further experimental data concerning the word level recognition problem, particularly with regard to vowels and diphthongs in varying consonant contexts, and (2) to present a graph-theoretic approach to employing sentence level grammar. The graph search strategy, based on the Planar separator theorem [R. J. Lipton and R. E. Tarjan, SIAM J. Appl. Math. 36, 177–189 (1979) and Venkatesh et al., Proceedings of the IEEE International Conference on Circuits and Systems'87, Philadelphia (in press)], is particularly useful in this problem where isolated regions of reliability in the message may be surrounded by unrecognizable acoustics. [Work supported by the W. R. Hearst Foundation, The United Cerebral Palsy Research and Education Foundation, and by N.I.H. under Grant No. 1R03RR02630.]
Tongue-jaw displacement variability in the fluent speech of stutterers and control subjects
Authors: Alfonso P. J. , Watson B. C. , Story R.
Published: October 2005

The x-ray microbeam installation at the University of Tokyo was used to compare supralaryngeal kinematic patterns of fluent utterances produced by a control subject and two stutterers. For the control subject, trial-to-trial variability in individual and combined tongue-jaw peak displacement for alveolar obstruent closure and release was equivalent to the variability in lip and jaw displacement for bilabial stop closure and release by a larger group of normal subjects [V. L. Gracco and J. H. Abbs, Exp. Brain Res. (in press)]. The stutterers demonstrated greater variability than the control in individual tongue and jaw displacement, and the combined tongue-jaw displacement variability was not less than the individual articulator variability. In contrast to the control, the stutterers achieved closure and release primarily by jaw displacement with little, and occasionally paradoxical, tongue displacement. The lack of covariability in tongue-jaw displacement, coupled with the dominance of a single member of an articulator complex, suggests that stutterers lack the same degree of precision and flexibility observed in normal speech motor systems to efficiently meet invariant object-level goals. [Work supported by NIH NS-13617.]
Tactile aids for the deaf
Authors: Goldstein Moise H.
Published: October 2005

In a recent article [C. E. Sherrick, J. Acoust. Soc. Am. 75, 1325–1342 (1984)], some noteworthy questions about tactile aids were posed. Among them were: “(i) What are the processing capacities of the skin?, (ii) what form of transducer system will provide a reliable and efficient display to the skin?, (iii) if not all speech features can be handled by the substitute channel, which are the important ones to emphasize?, and (iv) how should the target population be defined?” These questions will be considered in context of the present day. Several companies now sell tactile aids for amounts close to the cost of a quality hearing aid. The characteristics and marketing of these commercial aids will be indicated. The target population of children versus adults and prelingually deaf versus postlingually deaf will receive special consideration. At present, one may question whether tactile aids are effective sensory substitutes for audition; nevertheless, it is becoming clear that they can have important benefits. [Work supported in part by NSF and NIH.]
Coupled pendulum model for the middle ear
Authors: Nassef Ahmed M. , Finch R. D. , Gray L.
Published: October 2005

Models of the middle ear given in the literature (piston and lever, membrane and lever, two piston and lever) were studied by deriving their transfer functions, and the values of the parameters best fitting an experimental transfer function were derived for each model. It was found that none of these models could fit the data with the same physically realizable components over the whole audible frequency range. Consequently, a new model was sought, based on an inspiration from Békésy's observation of rotational motion of the tympanum. That the middle ear acts as a two-degree-of-freedom system comprised of two coupled pendulums is suggested. Such systems have an inherent out-of-phase motion at high frequencies. That the malleus and part of the tympanum could comprise one rotating unit and that the incus and stapes could comprise the other is also suggested. The incudo-malleol joint could then be represented by the coupling and fulcrum in the model. Such a model has been found to meet the objective of fitting the transfer function over the entire frequency range. It is possible that such models can have application in prosthesis design.
On the measurement and calibration of ear impedance and its relation to the frequency of test signal
Authors: Rao Yu-An , Liang Zhian , Carterette Edward C.
Published: October 2005

Experimental measurements and comparison of calibrated equivalent volumes of acoustic compliance were carried out with a probe set under different lengths of tube neck and diameters of coupling mouth. The relationship between equivalent volumes of acoustic compliance was a monotonic function of frequency for test frequencies below 500 Hz, but changed to a V-shaped function of frequency as test frequency was raised higher than 800 Hz. In cases where neck length ranged between 0 to 5 mm and the coupling diameter range between 1 and 2 mm, the maximal calibration error caused by the interaction of coupling mouth diameter and tube-neck length reached 0.4 ml for low frequencies; the maximal calibration error was much larger for high frequencies. In addition, comparisons of five different calibration cavities were carried out on, for example, Madsen and Chinese laboratory and clinical types. On the basis of these measurements on different cavities, it is proposed to take as a standard the value of 2 mm for both the tube-neck length and the coupling diameter.
Functional gain measurement of both amplitude and phase characteristics
Authors: Levitt Harry
Published: October 2005

The principle underlying the measurement of functional gain in hearing aids is that of comparing the stimulus level at threshold for the test condition (e.g., the aided condition) with the threshold level for a reference condition (e.g., the unaided condition). This technique is extremely useful but is limited, in its present form, to the measurement of amplitude-frequency characteristics only. The technique has been extended to the measurement of phase-frequency characteristics by introducing a secondary reference, a sinusoidal signal delivered to the ear by an alternate route (e.g., by bone conduction). The signal generated by the system under test is adjusted in amplitude and phase so as to cancel the secondary reference signal. The cancellation is done subjectively with the test system in situ. The signal generated under the reference condition is canceled in the same way. A comparison of the two sets of adjustments needed for cancelation determines the functional gain of the system with respect to both amplitude and phase.
Analytical concepts and models for calculating hearing protector attenuation
Authors: Shaw Edgar A. G.
Published: October 2005

In principle, the ideal hearing protector is a rigid airtight cover or plug that encloses a volume of air in contact with the eardrum and is sealed to an immovable object (the head or the external ear) by a resilient airtight cushion or interface. According to this simple view, the sound attenuation curve is solely dependent on a few lumped elements: the mass and area of the cover or plug, the acoustic impedance presented by the enclosed space, and the stiffness and mechanical resistance of the cushion or interface. In practice, the attenuation is also dependent on air leakage, body-conducted sound, the lack of rigid support, wave effects, and mechanical imperfections. These factors and others have been measured, estimated, and modeled with considerable success though perfect agreement between theory and experiment remains elusive. So, perhaps there is still room for further work of a fundamental nature. In the meantime, despite their limitations, the classical analytical models continue to provide an invaluable foundation for hearing protector design.
Noise attenuating earphones for audiometric testing
Authors: Killion Mead C. , Berger Elliott H.
Published: October 2005

Tests of the noise excluding properties of the TDH,50P/MX-41AR, the Audiocup, and the ER-3A insert earphone were performed in a diffuse-field facility complying with ANSI S12.6-1984. Data on attenuation were obtained monaurally with the nontest ear plugged and muffed. Results generally agreed well with previously reported measurements. A broadband noise, shaped by a multifilter, allowed a direct test of the ANSI S3.1-1977 permissible background noise levels for testing to audiometric zero under TDH-39/MX-41AR headphones. This “ANSI noise” raised the average thresholds of 15 normal-hearing test subjects by 3 to 5 dB at the 500- to 4000-Hz octave frequencies. With a noise shaped to the less stringent OSHA-1983 regulation, average thresholds were raised 9 to 17 dB. Introduction of an “ENT office noise” with 55 dB(A) overall level raised average thresholds at those frequencies by 11, 5, 1, and 0 dB with the Audiocups and less than 2 dB with the recommended fully (“deeply”) inserted ER-3A eartips. Measured threshold elevations agreed closely with predictions based on a critical ratio calculation utilizing actual sound field noise levels and measured attenuations. A conservative rule of thumb for testing to audiometric zero with the ER-3A earphone appears to be an office noise level of 45 dB(A) or less.
Piano stringing-scale design
Authors: Sanderson Albert E.
Published: October 2005

Stringing-scale design in pianos comprises the specification of the speaking length of each note, the number of strings per note (unichord, bichord, or trichord), the diameters for all plain-wire notes, and the diameter of the core and diameter and length of the copper winding for all loaded strings. These factors control the inharmonicity and tension of each string, and control of both is essential for excellent volume, tone quality, and balance of sound from baas to treble in a fine grand piano. While there is no accounting for taste, there is general agreement on which pianos sound best. Design rules have been derived based on these pianos, as well as on a large number of poor pianos, that reliably predict what ranges of the above design parameters will “sound good.” In general, the larger the piano, the more tension and the less inharmonicity it must have for excellent tone quality. Inharmonicity must also be carefully controlled to achieve perfect tunability. This is a rare quality that allows an instrument to be tuned so well that every musical interval (when played in ascending sequential semitones) increases smoothly and evenly in beat rate.
Longitudinal vibrations in piano strings
Authors: Podlesak Michael , Lee Anthony R.
Published: October 2005

The percussive excitation of a piano string by a hammer is expected to produce longitudinal string vibration components in addition to the desired transverse ones [e.g., Yanagisawa et al., J. Acoust. Soc. Jpn. 33, 412–416 (1977)]. However, so far little quantitative information exists in current acoustics literature on the contribution of such longitudinal components to the radiated sound of a piano. Our investigations revealed the presence of intial components of radiated sound generated by the longitudinal string vibration mechanism. These components, coined as the precursive sound, appear distinctly ahead of the main body of sound that is almost entirely due to transverse string vibration. Our experimental data on the longitudinal modes in piano strings indicate that the most apparent contribution to the radiated sound occurs in the attack transient of tones in the low bass register. For the lowest bass tones, the sound-pressure level (SPL) of the precursive sound may be only 10 to 20 dB below the overall peak SPL and the decay rate of the order of 100 dB/s. [Work supported by A.R.G.S. and C.T.E.C.]
Analysis and synthesis of piano tone
Authors: Reinholdt Astrid , Jansson Erik , Askenfelt Anders
Published: October 2005

Signals from a grand piano, consisting of the string velocity and the sound in the room, were recorded. The signals were analyzed with regard to waveform and spectral development in time. The analysis, as well as a listening to the recording, revealed a prominent initial thump in the room signal that preceded the tonal string sound. This attack sound was not present in the string velocity signal. Piano tones were synthesized by modeling the analysis results in an additive computer synthesis. Important features in the synthesized piano tone, such as spectral envelopes, initial thump, inharmonicity in strings, and multiple stringing, are illustrated by sound examples.
Vocal register change: A study of perceptual and acoustic isomorphism
Authors: Keidar Anat
Published: October 2005

This study focuses on the perceptual nature of chest and falsetto registers, and on the degree of correspondence between perception and several acoustic measures. Fifteen target notes, ranging from G♯3 to A♯4, were sung by a male and a female subject in the context of ascending and descending sequences on the vowels /i/ and /a/. Register transitions were elicited by setting strict constraints on production, and by minimizing auditory feedback. Segments of 1-s duration were extracted from the target notes, digitized, acoustically analyzed, and perceptually judged by ten trained listeners. Multidimensional scaling and hierarchical clustering analyses were utilized to capture the dimensionality and the internal structure of perceptual data sets derived from pairwise similarity ratings. Similar analyses of the acoustic data sets provided a means for evaluating the congruence of each acoustic variable and perception. Optimal spatial representation of the perceptual data required no more than two orthogonal dimensions, with the quality attribute represented by the dominant dimension. The acoustic variables which exhibited the highest degree of isomorphism with perceived registers were characterized by differences in frequency spectra obtained from a set of 1-oct bandpass filters, and by F0/harmonic ratio. The representation of pitch differences was reflected only in the internal ordering of the stimuli within register, but did not affect the perceptual discontinuity between registers.
Progress toward more intuitive programming of FM synthesizers
Authors: Gibian G. L. , Clements D. R. , Harnden E. N. , Bort D. L.
Published: October 2005

As was reported last year, work has been done to make the programming of new tone colors on FM synthesizers more intuitive for composers and musicians. The logarithmic relations between modulator, carrier, and envelope level parameters on commercially available instruments and corresponding index of modulation and output amplitudes in standard FM synthesis equations have been empirically determined. The relations have been incorporated into a tutorial computer program that displays the waveform and corresponding spectrum after synthesis parameters are entered in either form. With the program, users can gain familiarity with the spectra of FM-synthesized sounds, which can be quite complicated for synthesizers using four or six oscillators in various configurations. Work is currently being done to calibrate feedback and envelope rate parameters and to develop software to go in the opposite direction, determining FM parameters to approximate spectra with complicated and time-varying shapes. Ultimately, such software should choose the configuration of oscillators as well as other parameters to create the perceptually closest approximation to the desired spectral characteristics.
An evaluation of matched field processor performance with environmental mismatch
Authors: Dicus Ronald L.
Published: October 2005

The matched field processor is enjoying a technical renaissance because of increased computer computation speeds and environmental modeling capability. Its performance, however, is degraded by error or mismatch in waveguide steering vectors (theoretical fields) and by ambient noise. The effects of error in sound velocity profile, water depth, array depth, and sensor positions will be discussed in relation to their effect on source location bias, peak height, and peak width as a function of mismatch strength, frequency, range, and array length. Noise effects are not considered. To gain insight, the processor output was investigated for a simple multipath signal environment in which acoustic energy travels along straight line trajectories but with allowance for different effective wave speeds. At sufficient ranges it can be shown that the processor is equivalent to a linear sum of focused beamformers, each steered to a particular multipath. Error in the waveguide steering vectors has the effect of differentially rotating theoretical beams relative to true field beams, resulting in localization bias and peak height reduction. Ambiguous peaks are caused by rotation of a theoretical beam for one multipath onto the true field beam of another multipath. These effects will be discussed with numerical examples.
Passive ranging as an inverse problem
Authors: Sullivan E. J.
Published: October 2005

A passive ranging technique is presented which uses SNAP, the SACLANT Centre's normal-mode model. A set of linear equations are obtained that allow a maximum likelihood estimate of the range of an acoustic source to be directly computed using any desired combination of modes. This is in contrast to the matched-field techniques that use a search over forward solutions, each of which assumes a particular source location. The sensitivity of the technique to errors in the assumed sound velocity profile and tilting of the 16λ vertical receiving array is studied. Also, the effect of both white and colored noise is investigated. Results indicate that, for the scenario considered (Summer profile in the Mediterranean with a water depth of 130 m and source ranges of 10 and 25 km), the method can be quite robust to sound velocity profile errors on the order of several m/s and array tilts on the order of 1.5°. Solutions were obtained with input signal-to-noise ratios as low as − 17 dB.
Simulation of matched field processing for convergence zones in a strong bottom field
Authors: Gordon David F.
Published: October 2005

Below 30 Hz, the convergence zone energy can be smaller than the bottom reflected energy. Matched field simulations using a normal mode program give narrow, irregular correlation peaks for target vectors taken from the complete field. Target vectors computed using only modes representing convergence zone energy are then processed against the complete acoustic field. A much broader, smoother correlation function is obtained. Target vectors are then constructed that are equivalent to delay and sum beamforming at specified angles. These vectors give correlation functions that resemble those for convergence zone energy, and illustrate the relationship between matched field processing and beamforming.
Experimental determination of modal depth functions from covariance matrix eigenfunction analysis
Authors: Wolf Stephen N.
Published: October 2005

A low-frequency sound field in a shallow-water duct is usually represented by a set of discrete normal modes, each of which is characterized by a unique vertical pressure amplitude depth function. In many applications, such as matched-field signal processing, it is important to have accurate determinations of these depth functions, which are usually calculated from normal-mode models. By using a densely populated vertical array spanning the water column and a large time-bandwidth test signal, in some circumstances the normal-mode functions of the duct may easily be obtained by diagonalizing the cross-spectral density function of the received signal. The condition required for using this technique is that, over the bandwidth used, the fields of individual modes must be mutually incoherent so that the cross-spectral density matrix is the sum of individual modal diads, making the modal depth functions the same as the matrix eigenfunctions. Experimentally determined mode functions of orders 1 through 4 are compared with theoretical results.
Flapping of apical stops in American English
Authors: Mitleb Fares
Published: October 2005

One fundamental assumption in all theories of phonology has always been that neutralization rules have the power to obliterate the contrast between segments in certain environments. For example, American English is well known for its neutralization of intervocalic, poststressed /t/ and /d/ to an apical “flap” [ɾ]. However, acoustic analysis of five pairs of English words produced by five native speakers of American English revealed that flapping of apical stops is a near-neutralization process. Furthermore, in a listening test, American listeners were able to distinguish underlying /t/ and /d/ with about 69% accuracy—significantly better than chance. This suggests that segmental feature analysis oversimplifies the speech production and perception processes, since it states in advance the facts to be accounted for in phonology. Results of this study seem to call into question the current formulations of neutralization rules and related concepts. The findings will be interpreted in terms of their consequences for the presence of temporal implementation rules. [Research supported by Yarmouk University, Jordan.]
Effects of pragmatics on phonetic variables
Authors: Port R. , Crawford P.
Published: October 2005

It has been shown that the supposed neutralization of German minimal pairs like bunt and Bund is incomplete [J. Phonet. (1986)] since small but consistent differences can be found in phonetic variables. This permits listeners to guess with better-than-chance accuracy. But, since the distinction is very small, a question arose as to whether speakers can control the amount of difference they can produce between the two categories. In an experiment speakers were given a variety of tasks involving pronunciation of a small set of minimal pairs of the type bunt-Bund. First, they read the words within a long list of sentences so that their attention was diverted away from the test words. Then carrier sentences with the words in adjacent sentences were read, and finally German sentences comparable to, “No, I didn't say bunt, I said Bund,” were read. Analysis of temporal measurements from the words showed that speakers did produce more distinctive pronunciations in contexts where their attention was drawn to the contrast, and even more when trying to distinguish the pronunciations for a listener. This is evidence of graded phonetic control even when speakers have faint awareness at most that a distinction is made. [Research supported by NIH, HD12511 and NSF.]
Effects of voicing, place, and vowel context on VOT for French and English stops
Authors: Rochet Bernard L. , Nearey Terrance M. , Munro Murray J.
Published: October 2005

Preliminary results in a study of VOT in the production of French initial stops (recorded from eight native speakers) indicate a significant interaction of voicing state, place of articulation, and vowel identity in /CVk/syllables. While some of the trends observed are similar (e.g., VOT for high vowels is generally longer for that of non-high vowels), the exact pattern of interactions does not agree with that found for American English (R. F. Port and R. Rutonno, J. Acoust. Soc. Am. 66, 654–662 (1979)]. Results from a larger-scale measurement study comparing VOT production in French and Canadian English will be discussed. Interaction effects that depend explicitly on categorical (as opposed to purely acoustic) context have been shown to be reliable in VOT production experiments [Port and Rutonno (1979)]. Results of cross-language perceptual experiments (using VOT continua in which vocalic context and place of articulation cues are varied as parameters) designed to test the perceptual reliablity of such effects will be discussed. [Work supported by SSHRC.]
Effects of consonant length on vowel-to-vowel coarticulation in Japanese
Authors: Smith Caroline L.
Published: October 2005

Vowel-to-vowel coarticulation across consonants can be seen as evidence of overlap between the articulatory gestures of the vowels. Further evidence for the organization of the gestures can be found in contextual variation in the durations of the vowels. This acoustic study of Japanese examines the effects of geminate consonants on the durations and the F2 values of the surrounding vowels in VCV utterances. Because of the syllable structure of the language, geminate consonants in Japanese might be expected not to close the preceding syllable, eliminating this potential source of vowel shortening. In agreement with this hypothesis, vowels did not shorten before geminate consonants (in fact they lengthened), and the second vowel affected the formants of the first vowel less across geminate than across single consonants. [Work supported by NSF.]
Phonetic reality and phonological prediction: Stress clash and rhythm in English
Authors: Johnson Keith , Evans Dorothy
Published: October 2005

Cooper and Eady [J. Mere. Lung. 25, 369–384 (1986)] recently tested some predictions of metrical phonology only to find a lack of empirical support for some important aspects of the theory. This report will present the results of a replication and revision of one of their experiments. The phonological prediction being tested in this experiment is that the rhythm of an utterance will be adjusted toward isochrony is cases of stress clash (adjacent stressed syllables). In a pilot study it was found that in normal productions of test sentences the findings (or rather nonfindings) of Cooper and Eady were replicated. However, when subjects were instructed to “speak up,” there was a tendency toward rhythmic adjustment of the duration of words involved in the stress clash. In the study to be reported in this paper, subjects produced stress-clash sentence pairs once normally and once carefully (the instructions were “as if you were talking to someone who might have a hard time understanding you”). The results of the pilot experiment seem to indicate that speakers do in some circumstances adjust the rhythm of an utterance in response to stress clash. This pattern of results raises some questions about what linguistic “competence” is being described by the phonological theories tested.
Using metrical phonology to synthesize speech
Authors: Reilly William
Published: October 2005

In this experiment synthesized reiterant speech is compared to natural reiterant speech. Using multiple linear regression, equations are obtained which take grammatical information (e.g., syllable weight, word boundary, lexical stress) of natural speech syllables as input and produce as output information sufficient to predict the timing of the corresponding reiterant speech in nonphrase final position. A corpus of 35 phrases was spoken reiterantly by three speakers, using the syllable sa as the reiterant syllable. Measurements of the duration of the reiterant segments were made automatically from the digitized speech and constitute the final dependent variable. Each syllable is grammatically described as a string of binary variables determined from metrical phonology [Liberman and Prince (1977)]. After calculating the predicted segmental durations of a reiterant phrase, the original speech was modified to fit these predictions using the waveform editor of ILS. The resulting synthesized speech is then judged by comparing it to the original reiterant speech of the three speakers. The success of this experiment suggests that the same task might be performed for natural speech, and that the grammar is tied more closely to production and perceptual mechanisms than previously shown. [Work supported by NSF.]
The phonological domains of final lengthening
Authors: Beckman Mary E. , Edwards Jan
Published: October 2005

A syllable at the end of a phrase is considerably longer than it would be phrase-internally. Similarly, a stressed monosyllable is generally longer than any identical syllable separated from the word's edge by one or more unstressed syllables. Two sets of experiments have been designed to determine the phonological domain of these effects. The first compared target syllables at various distances from the ends of words ([pε] in pep, pepper, peppermint; [pa] in pop opposed, poppa posed) in sentences where they either did or did not precede an obligatory intonational phase break. These experiments showed that (1) there is a smaller word-final effect distinct from the substantial phrase-final lengthening at intonational boundaries, and (2) the word-final effect must also be a boundary effect rather than a result of stress timing, since it occurred even in the pop opposed-poppa posed utterances, where the target syllable was always followed by exactly one unstressed syllable. The second set of experiments tests whether word-final lengthening is affected by pitch-accent and stress placement, or whether it defines a phrasal unit independent of metrics.
Metrical structure of initial syllables in English
Authors: Cutler Anne , Carter David
Published: October 2005

Cutler and Norris [J. Acoust. Soc. Am. Suppl. 1 77, S39 (1985)] provided evidence for a segmentation strategy in continuous speech perception, whereby a word boundary is postulated, and a lexical access procedure initiated, at each metrically strong syllable. In the present study, the likely success of this strategy was estimated against the characteristics of the English vocabulary. Two computerized dictionaries and two frequency counts were consulted. The dictionaries list approximately three times as many words beginning with strong syllables (i.e., syllables containing a full vowel) as beginning with weak syllables (i.e., syllables containing a reduced vowel). Frequency counts reveal that words beginning with strong syllables have a mean occurrence frequency nearly twice that of words beginning with weak syllables. These findings motivate an estimate for everyday speech recognition that approximately 85% of lexical words (i.e., excluding function words) will have strong initial syllables. This estimate was tested against a corpus of 190 000 words of spontaneous British English conversation [J. Svartvik and R. Quirk, A Corpus of English Conversation (Lund, Gleerup, 1980)]. Ninety percent of lexical words in this corpus were found to begin with strong syllables. [Research supported by the Alvey Directorate, United Kingdom.]
Sex differentiation cues in the voices of young children of different language background
Authors: Karlsson Inger , Rothenberg Martin
Published: October 2005

Children, aged 3–8 years, speaking different native languages, were recorded and speech samples from these children were played back to adult listener groups, also of different language background. The listeners were asked to judge the sex of the child. The children were native speakers of English, Finnish, or Swedish and the listeners were native speakers of Finnish, Swedish, English, or Chinese. Speakers and listeners from different language backgrounds were used to find out if the differences in boys' and girls' voices were socially acquired or innate. The average right judgment was 66% over all speakers and listeners, with no strong tendency for a higher percentage of right answers for children speaking the listener's own language. The results from the listening tests have been compared to different acoustic measurements of F0, vowel formants, and speaking rate. No apparent correlation between perceived sex and these measurements has been found.
Age-sex variations in maximum performance measures of speech production
Authors: Kent Ray D. , Kent Jane F.
Published: October 2005

The maximum performance measures of speech production include: phonation volume, maximum phonation time, maximum expiratory pressure, maximum vocal SPL, physiological vocal frequency range, maximum articulatory force, and maximum syllable repetition rate. A survey of the normative data seemed in order, given the frequent clinical use of these measures and the availability of a large, although scattered, archival database for normal speakers. This report reviews published data for each measure and considers the adequacy of these data for clinical application. The data are found to be deficient in several respects: (1) the effects of subject age and sex are incompletely documented; (2) test procedures are not standardized; (3) the validity of a maximum performance estimate is open to question for most, if not all, measures; (4) the variability of the data within and across studies is very large; and (5) a theoretical framework for the interpretation of the measures is either lacking or deficient. Recommendations are offered to correct some of these problems, but the major conclusion of this report is that measures of maximum performance lack validity and efficiency for general clinical application. Summary tables of the normative data are available upon request. [Work supported by NIH.]
Variability differences in the speech production in two age groups of adult females
Authors: Morris Richard J. , Brown W. S.
Published: October 2005

The purpose of this study was to examine the variability between the speech produced by two age groups of adult females, a young adult group and a geriatric group. The 25 women in each group phonated three productions of the vowel /a/ for 5 s at three effort levels—maximum, comfortable, and minimum. Recordings of these productions were digitized and analyzed for mean intensity and intensity distribution. The women also repeated a series of CV, VCV, and VC syllables using the consonants /p/, /b/, /t/, /d/, /s/, and /z/ combined with the vowel /a/, in the carrier phrase “Speak_____again.” Intraoral air pressure and the voicing signal were recorded to provide vowel and consonant durations, voice onset times, and peak intraoral air pressure. The F-max test for homogeniety of variance was used to compare the variability between the two age groups. The older speakers exhibited significantly greater variability than the younger speakers for the dependent variables, peak intraoral air pressure, consonant duration, vowel duration, voice onset time, and the minimum effort level of speech intensity. The greater variability of production exhibited by the older speakers could be a factor in the perception of older speakers.
Acoustic-phonetic correlates of language development
Authors: Bauer Harold R. , Nelson Lauren
Published: October 2005

Phonetic contrast has been suggested as a cognitive operating principle underlying the continuity of infant phonetic development [H. R. Bauer, J. Acoust. Soc. Am. Suppl. 1 75, S45 (1984)]. Phonetic contrast was estimated in the current study using the phonetic product (PP) estimator weighted to the same eight American English sound-class frequencies. The PP was a result of the multiplication of the number of eight different contrasting sounds per minute after weighting and was summarized from recordings of mother-infant interactions. The results from four children were compared when each was 1 and 2 years old. Associated measures of language development at 2 years of age were also compared for predicted order based upon the subject's 1-year data. As an estimator of phonetic contrast, PP and its acoustic correlates in 1-year-old infants, were predictive of most of their PP and associated language variables at 2 years of age.
The effect of speaker gender on word recognition
Authors: Wasowicz Jan M. , Elliott Lois L.
Published: October 2005

The effect of speaker gender on word recognition was investigated using a forward-gating paradigm [F. Grosjean, Percept. Psychophys. 28, 267–283 (1980)]. Stimuli varied in number of syllables (1 or 2) and gender specificity (male-, female-, or neutral-oriented). The stimuli constituted the final word of a declarative sentence (e.g., “I recently bought a new pipe/dress/bike”). Each sentence was spoken by both a male and a female talker, recorded and digitized before the final words were gated. The shortest gate for each word was the initial 30 ms. Successive gates were increased in duration by 30 ms. The purpose was to determine whether words would be identified at shorter gate durations when the word was appropriate to the speaker's gender, as compared to when it was not. The results suggested that speaker gender facilitated the recognition of gender-appropriate words and inhibited the recognition of gender-in-appropriate words. Results will be discussed with respect to current models of word recognition. [Work supported by Dissertation Year Grant, Northwestern University.]
Selection of resilient mounts for protection of fragile equipment considering foundation and equipment structural admittances
Authors: Himelblau Harry , Rubin Sheldon
Published: October 2005

In 1962, a group of structural dynamicists under the auspices of SAE Committee G-5 on Aerospace Shock and Vibration developed a procedure on the above subject, which was published as SAE Doc. AE-3. This procedure was restricted to the assumption of rigid equipment structure under translational excitation and response. Five years later in an unpublished report, Rubin extended the procedure to permit the consideration of arbitrary admittances of both equipment and foundation. This extension is reviewed in this presentation, including a simple criterion for mount adequacy, a graphical method for verifying that adequacy, and an overlay for the rapid selection of mount stiffness and damping. Mount restrictions to avoid bottoming under sinusoidal and random excitation are also discussed.
Acoustic characterization of some commercially available closed cell rubbers and corprene
Authors: Caille Gary , Jarzynski Jacek , Rogers Peter
Published: October 2005

Three closed cell and two corprene rubbers (manufactured by Rubatex and Groendyk Corporations, respectively) with Neoprene and nitrile bases have been experimentally investigated in the frequency range of 10 to 70 kHz. These materials contain approximately 50% air and simulate a pressure release surface with reflection coefficients near −0.95. The characterization includes longitudinal sound speed and transmission, reflection, and absorption coefficients as functions of incident angles and frequency. The dynamic (complex) Young's modulus and loss factors have been determined by the longitudinal resonance method. Poisson's ratio is assumed to be 0.499 which allows prediction of the shear modulus. A comparison between the experimentally determined reflection and transmission coefficients with theoretical values [D. L. Folds and C. D. Loggins, J. Acoust. Soc. Am. 62, 1102–1109 (1977)] is presented. Prediction of the moduli using contemporary composite models will also be presented.
A study of a parametrical system with a clearance type nonlinearity
Authors: Comparin R. , Singh R.
Published: October 2005

Gear rattle is one of the major noise and vibration problems affecting lightly loaded drives. Gear rattle is a complicated, nonlinear vibration, characterized by backlash induced vibro-impact between meshing gears. For geared systems with a constant driving torque, rattle is the result of a parametric excitation due to mesh stiffness variation and transmission error. This work represents a fundamental study of the vibro-impact problem in a parametrically excited mechanical system with clearance. Specifically, this work describes the frequency domain characteristics of a parametrically excited single degree of freedom system with a clearance type nonlineartry. The stability of steady-state solutions are also considered. An approximate analytical technique is used and results are compared with digital (numerical integration) simulation results.
High-frequency audiometry and intersubject variations of ear canal geometry
Authors: Stinson Michael R.
Published: October 2005

An extension of current audiometric techniques to frequencies greater than 8 kHz is highly desirable but difficult because of the large intersubject scatter in hearing threshold data at these frequencies. One of the main sources of scatter is the variation between subjects of size and shape of ear canal. This factor is examined by considering a model of an audiometric headphone mounted over the ear of a subject. The ear canal is treated in detail using a horn equation approach to calculate the pressure distribution along its length, given its exact geometry; the calculation can be repeated for different canal geometries with everything else (headphone, eardrum impedance) unchanged. Above 8 kHz the transformation from headphone input voltage to sound pressure at the eardrum is a function which depends on frequency, showing peaks at frequencies that depend critically on the choice of geometry. For a realistic range of ear canal lengths and shapes the eardrum pressure (and, hence, the apparent threshold) can vary by as much as 20 dB between subjects at a specific frequency, for the same input voltage. Conventional audiometric techniques must be modified considerably if they are to be applied above 8 kHz.
The interaction of impulse and continuous noise: Energy and spectral considerations in the production of hearing loss
Authors: Roberto Michele , Ahroon William A. , Davis Robert I. , Hamernik Roger P.
Published: October 2005

Realistic industrial noise environments containing impulsive and continuous noise were modeled using a 5-day exposure paradigm that produces an asymptotic threshold shift (ATS). Pre- and postexposure measures of hearing thresholds were obtained on 96 chinchillas using evoked auditory responses (EAR). Six control groups were exposed to octave bands of noise at 0.5, 2.0, and 4.0 kHz at 95, 90, and 86 dB SPL, respectively, or impacts of 113, 119, or 125 dB peak SPL presented once per 1, 4, or 16 s, respectively. Nine interaction groups were exposed to combinations of an impulse and continuous noise. The greatest spectral overlap of energy occurs between the impulse and the 0.5 kHz octave band of noise. Although each of the different impulse noise exposures were balanced to produce an equal energy exposure, an exacerbation of hearing loss was produced in animals exposed to the 119- and 125-dB impacts in combination with the low-frequency (0.5-kHz) continuous noise. This synergistic effect gradually disappears when the spectral overlap between noises is reduced. [Research supported by NIOSH.]
Calibration and the comprehension of synthetic and natural speech
Authors: Zeigler Bonnie L. , Boggs George J. , Kaufman Leah S.
Published: October 2005

Investigations of “calibration” (the relationship between knowledge and the self-assessment of knowledge) have found that humans reading expository text cannot accurately judge their ability to draw inferences from the material read. Whether low calibration was related to the inference process or to the act of reading by presenting passages aurally, as either natural or phoneme-synthesized speech is examined. Sixty-four adults, divided into natural and synthetic-speech groups, heard 15 passages, with half the subjects permitted to listen twice. After each passage, subjects rated their comprehension, then judged the veracity of an inference drawn from the text. Calibration quotients, derived from the ratings and performance scores, were significant for both synthetic and natural groups. Performance, ratings, and calibration were slightly higher for natural versus synthetic subjects, but the difference was reliable only for confidence ratings. Thus previous low calibration may be more related to presentation mode than to inference processes. Better calibration for listeners may be due to a closer relationship between inferences and listening, which encourages extraction of themes as opposed to detail, than between inference and reading.
Vibration analysis of a hammer-shank system
Authors: Suzuki Hideo
Published: October 2005

The transient motion of a hammer-shank system is mathematically analyzed using a modified form of the Myklestad method. The hammer is modeled as a mass-spring system with a nonconstant spring coefficient. The shank is divided into 13 elements, where each element is assumed to have a uniform cross section. The effect of the shank stiffness, the hammer velocity, and the initial deformation of the shank in the force-time pattern applied by the hammer to an ideally rigid string are investigated. The results show that the shank deforms significantly during the hammer-string contact period. It is also shown that the force-time pattern changes significantly when an initial deformation of the shank is introduced. Some of the theoretical results are compared with experimental results. (This study was conducted while the author was at CBS Technology Center, Stamford, CT 06905, from 1981 to 1985.)
Piano hammer: A nonlinear model compared to experiment
Authors: Boutillon Xavier
Published: October 2005

This paper presents a nonlinear model for the hammer, its experimental determination, and comparisons between simulated and recorded movements of strings and hammer during their interaction. It is first shown how closely the impact velocity of the hammer is the only input parameter that governs the collision of the hammer with the strings and therefore the quality of the sound. However, this quality is highly dependent on the magnitude of the impact velocity. So, a nonlinear model is required to describe the hammer's behavior. It consists of the association of a mass with a nonlinear, hysteretic spring whose characteristics are experimentally determined under realistic playing conditions. Both nonlinearity and hysteresis are fit by analytical relationships. This model, when associated with a simple flexible string model, allows a numerical simulation of the movements of both hammer and strings. These are compared to the measured vibration of a string and to the measured acceleration of the hammer. In addition, results are presented regarding the efficiency of the hammer impact.
Bottom effects on matched-field localization performance in the North Pacific
Authors: Fizell R. G. , Porter M. B.
Published: October 2005

PACIFIC ECHO was an experiment conducted jointly by the Naval Research Laboratory (NRL) and Defence Research Establishment, Pacific (DREP) in May–June 1986. Vertical array measurements of a 15-Hz cw signal projected by the NRL MK-VI source, towed at a depth of 100 m, were taken on the 675-m-long DREP array at both thinly (< 50 m) and thickly (> 500 m) sedimented areas. The array was located in separate cases in the direct path and the shadow zone, and the top sensor was at a depth of approximately 350 m. Matched field processing between theoretical and measured fields was applied to this data set in order to perform range-depth localization. Both a linear (Bartlett) and a nonlinear, minimum-variance (Capon) estimator were employed using theoretical fields generated by a normal modes program. The bottom model plays an important role in the shadow zone where acoustic energy is received predominantly via bottom interacting paths. The thin sediment site, in turn, is especially interesting because of the interaction with the elastic subbottom. The effect of differences in measurement site (thin or thick sediment), source-received separation, and processor estimator on performance of the matched field processor are discussed.