bluuebunny/crossref_metadata_2025 huggingface dataset:
Direction-specific acoustical aftereffects
Authors: Ehrenstein W. H.
Published: October 2005

An experimental method for the investigation of direction-specific characteristics of the auditory system is presented. The subjects were exposed to narrowband signals of 100 Hz, 1 kHz, and 6 kHz mean frequency. Directed acoustic motion (adapting stimulus) was presented clockwise/counterclockwise) in three ways: (1) actual sound source motion (loudspeaker rotating around the subject), (2) simulated motion via earphones, varying interaural intensity (ΔI), and (3) simulated motion via earphones, varying interaural-time delay (Δt). Aftereffects in the opposite direction were observed in all three cases, but in case 3 (Δt) for 6-kHz signals only. Unlike the visual analogue (waterfall effect) no apparent countermovement occurred, but rather a shift in the localization of the stationary test stimulus (approximately 2°, 1.2 dB, 30 μs, respectively). The results provide evidence for direction specific auditory subsystems in humans, i.e., for null-point displacements caused by the adaptation of direction-sensitive movement detectors [cf. J. A. Altman, Exp. Neurol. 22, 13–25 (1968)]. In support of physiological and anatomical findings (cf. Keidel, Neff, and Whitfield), the frequency dependence in case 3 (Δt) may indicate that the observed phenomenon is of cortical origin. [Based on the author's doctoral thesis, University of Göttingen (1977).]
On sound localization cues in the median plane
Authors: Morimoto M. , Nomachi K.
Published: October 2005

In order to make it clear which is more important for sound localization in the median plane, SP cues (spectral cues) or ID cues (interaural difference cues), two localization tests of sound sources simulated by a digital computer using measured individual head-related transfer functions (M. Morimoto et al., 9th ICA, H47 (1977)] were carried out. First, SP cues were presented to the subjects keeping interaural differences of all stimuli constant. Second, to the contrary, ID cues were presented to them keeping all spectra at one ear constant. The results of those tests are the following. (1) All subjects can localize stimuli with only SP cues. but they cannot localize so accurately as stimuli with the both cues. (2) They cannot localize stimuli with only ID cues at all. Those results show that SP cues are far more important than ID cues for sound localization in the median plane, however, that ID cues should not be neglected.
On the “time image” in lateralization
Authors: Bilsen F. A. , Cornelis J. G. , Raatgever J.
Published: October 2005

Lateralization of low-frequency waveforms is based on interaural time delays and intensity differences. To a large extent, time and intensity are tradable, i.e., a shift of a lateralized image due to a variation of time delay can be neutralized by an appropriate variation of intensity, and vice versa (“time-intensity trading”). Several experimental results have been reported which are difficult to reconcile with complete trading [e.g., Whitworth and Jeffress, J. Acoust. Soc. Am. 33, 925–929 (1961)]. This had led to the notion of a “time image” and a (separate) “intensity image.” The latter obeys time-intensity trading, whereas the first does not. As both images appear together in a lateralization experiment with conventional stimuli, it is difficult to separate them introspectively. This has caused many controversies in the literature. Here, we report the existence of at least one class of stimuli that evoke the time image only, and that are insensitive to intensity differences. These signals essentially are dichotically presented white noise, with a conventional (frequency-independent) interaural time delay τ and, in addition, an interaural 2π phase shift in one (or more) small frequency band(s) below 1500 Hz. Such signals evoke dichotic pitch images with a position that only depends on τ. Results will be reported and discussed in the context of current theories on binaural interaction.
Isoresponse temporal masking patterns in sensorineural listeners
Authors: Nelson D. A. , Turner C. W.
Published: October 2005

Pure-tone maskers (200 ms) were adjusted to intensities that just masked short (20 ms) pure-tone probe signals at low and at moderate sensation levels. (The probe is constant in both frequency and level during a masked threshold determination.) The delays between maskers and probes were varied to obtain what are called isoresponse temporal masking patterns. Results in normal-hearing listeners are consistent with classical isointensity temporal masking patterns that were obtained by previous investigators, and with isoresponse temporal masking patterns that have been obtained more recently [L. L. Vogten, J. Acoust. Soc. Am. 63, 1520–1527 (1978)1. Some sensorineural listeners required considerably less masker level for temporal masking (interference) to occur than did normal-hearing listeners, even when masker and probe were in a frequency region of relatively normal sensitivity. This result was obtained whether comparisons were made with probe signals at the same sound pressure levels or at the same sensation levels that were used for normal-hearing listeners. Temporal masking in some sensorineural listeners also extended over a greater delay time between masker and probe than for normal-hearing listeners. These findings have implications for current forward-masking techniques that obtain estimates of frequency selectivity, they also have implications for speech perception by some sensorineural listeners in difficult listening situations. [Research supported in part by NIH Grants Nos. NS10561 and NS12125.]
The range of spectral integration
Authors: Spiegel Murray F.
Published: October 2005

The present study examined the flexibility of the auditory system to integrate energy spread over a band of frequencies. Minimum spectral integration can be measured when a single tone is masked by various bandwidths of noise (a “critical-band” experiment); maximum spectral integration can be examined when a signal noise, of various bandwidths, is masked by wideband noise. The present study compares these two measures directly by employing the same stimuli and experimental procedures. Digitally synthesized noise, with essentially rectangular spectra (3000-dB/octave skirts), was used either as masker or signal. In the first case, when the masking noise bandwidth was varied, just-detectable signal level for a 1000-Hz tone increased at 1.7 dB/octave until Wm = 70–110 Hz and then remained essentially constant. In the second case, when signal bandwidth (centered at 1000 Hz) was varied, just-detectable signal level was essentially constant until Ws = 70–110 Hz and then increased at 1.7 dB/octave. The coincidence of the two breakpoints suggests a simple critical-band estimation procedure derived from two thresholds: a tone in wideband noise and a wideband signal in a wider-bandwidth noise. Based on the predictions for the energy-detector model, a 1.5-dB/octave slope implies an efficient spectral integration over the signal bandwidth. Combined with Green's similar slope, the present results indicate that the maximum limit of spectral integration may be at least 3 kHz wide. Additional results suggest abrupt spectral edges in masking noise without a wideband background slightly interferes with a simultaneous signal; the effect is similar to nonsimultaneous suppression/inhibition effects, although the cause may not be the same. [Work supported by NIH.]
Additivity and nonlinearity in forward masking
Authors: Penner M. J.
Published: October 2005

Two successful noise maskers, A and B, are presented prior to a click signal. In two separate forward masking experiments each of these maskers is presented alone in the same temporal relationship to the click as in the two masker condition. The levels of the single maskers are adjusted so that each alone produces the same amount of masking of the click. How much need the signal be increased to achieve threshold when the noises are presented in succession? If the auditory system were both additive and linear, a 3-dB increment would be required. If the effects of the maskers are additive at the time the signal occurs but single intensity is compressed, the signal level at threshold must be more than doubled. Empirically we find that the signal increases by about 10 dB. Additivity is shown in a separate experiment by adding a third masker C and finding that A and C produce the same masking effect as B and C. The results of these experiments are consistent with the hypothesis that the auditory system is additive but nonlinear. [Work supported by NIH.]
Effects of duration of fringe of noise and fringe of silence on psychometric functions
Authors: Osman E. , Tzuo P.
Published: October 2005

The effects of the packaging in time of broadband noise added outside of the signal interval for a brief signal already masked by simultaneous noise are reported. The signal was nominally 10 ms in duration and was either a 400-Hz tone burst or a broad-band noise burst. For “noise-fringe” conditions the additional noise was packaged about the basic 10-ms segment as a symmetrical and contiguous extension in time. For “gap-fringe” conditions noise was continuous in time except for a symmetrical gap of silence surrounding the basic 10-ms segment. Durations of noise fringe or gap fringe ranged from 0 to at least 95 ms. Complete psychometric functions were estimated for each condition for each observer in the form of paired slope and threshold indices. The results are viewed in consideration of the problems of theoretical slope-threshold relations, the critical masking interval, and relations between gated and continuous masking. [Work supported by NIH.]
Subharmonic pitch extraction or pitch memory?
Authors: McAdams Stephen E. , Wightman Frederic
Published: October 2005

Hourcast [J. Acoust. Soc. Am. 60, 405 (1976)] reported that a pure tone may elicit the perception of a subharmonic pitch when presented at a low S/N ratio, but not when presented at a high S/N ratio. Our replication of Houtgast's experiment suggests an alternative interpretation of the results, that the phenomenon may not be due to subharmonic extraction, but rather to the listener's memory of the components of the comparison tones. Following Houtgast's procedure, one or more of the components of a three-component harmonic complex was presented on each trial, but without the six-component comparison tone. On any trial the components were harmonics of one of two possible fundamentals, 6% different in frequency. They were presented both with and without a noise background, at four mean harmonic numbers. The listeners' task was to indicate whether the components belonged to the higher or lower fundamental. Results from highly trained musicians and from naive listeners were essentially identical to Houtgast's results, and suggest that judgements are made according to between-trial comparisons, rather than in reference to a pitch context formed by the comparison tone. The noise background had no effect. [Work supported by NIH NS12045.]
Physiology and anatomy of avian ear
Authors: Saito Nozomu
Published: October 2005

The structures of the avian outer and middle ears are furnished by the most extensive adaptive variations according to different ecological requirements. The cochlea with lagena is almost straight and cell arrangement in the cochlear duct is distinguished from the mammalian: Two types of hair cells lie in one continuous row, the cilia are inserted firmly into the tectorial membrane, the pattern of nerve innervation is quite different from that of the mammalian corti, and the orderly seqence of innervation on the basilar membrane is reserved obviously in tonotopical organization of the cochlear nuclei. Songbirds can hear most of the frequencies in their vocalization, while their ears are not the kind of specialization for communication seen in orthopterans and frogs: Recognition of conspecific songs involves in processing in the higher CNS rather than in the range of frequency alone. The behavioral relation of vocalization and hearing may light on tentative approaching the problem of pattern recognition in auditory CNS.
Estimation of effective mass and stiffness of the vocal folds from distributed models
Authors: Titze Ingo R. , Talkin David T.
Published: October 2005

The effective mass and stiffness of the vocal folds are the primary factors in the control of fundamental frequency. Since the soft tissue medium of the folds constitutes a distributed system, the equivalent lumped constants depend heavily upon the viscoelastic properties and the boundary conditions. We show an evolution of continuum models from a semi-infinite medium to the more realistic case where three boundaries are fixed and three boundaries are exposed to airflow. In order to compare lumped-constant parameters to distributed properties, a set of known surface stresses is applied at the exposed surfaces of a continuum model, mode impedances are defined, and the equivalent lumped constants are determined by resonance and asymptotic conditions of impedance curves. We show the dependence of the equivalent mass and stiffness upon the vocal fold length, depth, and thickness, as well as tissue properties such as orthotropy and incompressibility.
Prediction of vocal tract shapes in utterances
Authors: Ladefoged Peter , Lindau Mona
Published: October 2005

A previous paper showed how the vocal tract shapes of American English vowels can be generated from three formant frequencies. This algorithm has now been augmented and tested on short utterances containing predominately vocalic segments such as "Where were you a year ago?" Three subjects were recorded saying phrases of this type. Formant frequencies were determined every 10 ms and used to calculate possible underlying components of tongue and lip shape. These components were used to produce sequences of sagittal section diagrams of the vocal tract. Some consonantal effects were taken into account by means of simple rules (e.g., the tongue tip was moved towards a retroflex position when F3 was lowered). Given appropriate formant frequencies, plausible sequences of movement of the vocal organs were generated. Since the same set of formant frequencies can correspond to different vocal tract shapes, no claim can be made that these particular movements were used by these particular speakers. But, throughout most of the utterances, vocal tract shapes were generated that could have produced the observed formant frequencies.
Estimation of articulatory motion by a model matching method
Authors: Shirai K. , Honda M.
Published: October 2005

First, an effective method to describe the position of the articulatory organs is presented. The method relies on the statistical analysis of real data. The vocal tract shape is specified effectively by five articulatory parameters, the angle of jaw opening, two principal components for the various tongue shapes, lip parameter, and glottal parameter. Next, this articulatory model is used to estimate articulatory motion from speech waves. The articulatory parameters are estimated by minimizing the spectral error with some constraints. This is a nonlinear optimization problem and is solved by an iterative procedure. The power spectrum of the speech wave is composed of the vocal tract transfer function and the glottal wave characteristic. The spectral shape of the vocal tract transfer function is separated in such a way that the formant structure is preserved. Combined with a procedure to adjust the mean vocal tract length for each speaker, this method is very successful in estimating the articulatory parameters from vowel sounds. [Work supported by Ministry of Education Grant-in-Aid for Scientific Research No. 239005]
Parameter description of tongue point movements in the production of Japanese vowels
Authors: Sekimoto S. , Kiritani S.
Published: October 2005

The movements of several pellets on the tongue and the lower incisors in the production of Japanese vowels were observed by the x-ray microbeam method, and the displacements of the pellets were represented by a linear superposition of two major components: (1) a component linearly correlated with jaw movement and (2) the first principal component of the residual displacements. Accuracy in the approximation of tongue configurations for the five Japanese vowels were approximately the same for three subjects. The components derived for stationary vowels and continuous vowels were identical. The time function for these two parameters in the production of V1V2V1 test words were approximated by a step response function of a critically damped second order linear system. It was found that the time constant for the jaw movement was about 1.5 times greater than that for the front-back movement of the tongue. The duration of the step command for V2 appeared to be longer when V2 was a high and/or front vowel. [Work supported by Ministry of Education Grant-in-Aid for Scientific Research, No. 239005.]
Speech synthesis by rule from neurophysiological parameters
Authors: Imaizumi S. , Kakita Y. , Hiki S.
Published: October 2005

The adjustment of the larynx and articulation in the vocal tract for the utterance of Japanese words were investigated by means of a digital simulation of anatomical structure models. In order to control the contraction of each muscle involved in the models, neuromotor commands were generated by rules from phonemic input. The rules were obtained by the analysis of electromyographic data. The resulting movements of the larynx and the vocal tract were compared with observed data regarding the vertical displacement of the larynx, mouth shape, jaw opening, and lingual contact to the palate. Next, glottal sound was generated by a functional model combined with the model of the larynx, and a speech sound was derived by simulating the propagation of the glottal sound through the model of the vocal tract. The correspondence of the changes in the fundamental frequency and in the formant frequencies of the synthetic speech to those observed in natural speech was also discussed. [Work Supported by Ministry of Education, Japan.]
Spectra of wind, wave, and ship-generated noise at very low frequencies
Authors: Diachok Orest
Published: October 2005

Measurements of ambient noise at very low frequencies in deep ocean environments are reviewed in light of three proposed noise-generating mechanisms. Unpublished measurements by McGrath and Lawson, coupled with data reported by Perrone, reveal noise levels increasing with wind velocity to approximately the 3.5 power, and a small dependence of spectrum level on frequency in the vicinity of 10 Hz. These results are in accord with the predictions of the "turbulent wind" model proposed by Isakovich and Kuryanov. In the frequency range of 0.1–2 Hz, previously reported measurements of noise levels by Latham and others reveal a peak in the spectrum at about 0.3 Hz and lend credence to the Longuet-Higgins hypothesis that nonlinear interaction of water surface waves produce sound at twice the dominant surface wave frequency. In the vicinity of 1 Hz these data are characterized by spectra which fall off rapidly with frequency in quantitative agreement with recent predictions by Hughes. Above 1.5 Hz harmonic shaft and blade rate lines of ships may dominate noise levels at low sea states and in close proximity to traffic lanes.
Features of fully portable 1/3 octave real-time analyzer
Authors: Koshiroi Toshiaki , Ishizuka Susumu , Ono Itsuo
Published: October 2005

The 1/3 octave real-time analyzer is used especially for research of evaluation or reduction of environmental noise and vibration. Since it has been very expensive, large, and heavy, and dependent on external power sources, users were limited and the field operation was difficult. We have newly developed fully portable 1/3 octave real-time analyzer Model SA-24, which has 3.5-in. CRT display, measures 29(W) × 10(H) × 36(D) cm, weighs 8.5 kg and operates with internal rechargeable battery (about 4 hours continuous operation), AC line and external DC. The price has become as less expensive as 1/3 of other equivalent models. Model SA-24 has plug-in filters of multi-channel covering 31.5 Hz through 8 kHz for 1/3 or 1/1 octave band analysis and 1 Hz through 250 Hz for 1/3 octave band analysis. The band level is detected by RMS detector at crest factor 3 (± 0.5 dB), and the averaging time constant can be selected between 0.1 s and 10 s. The dynamic range of level detection and display is over 40 dB, and instantaneous and maximum level hold can be made. The spectrum pattern can be read out to level recorder or to other instuments.
New sound level meters and their versatile options
Authors: Oho Itsuo , Yoshikawa Kyoji , Koshiroi Toshiaki
Published: October 2005

The IEC draft (consolidated revision of IEC Publ-123 and Publ-179) was adopted for our new sound level meters, models NA-20 and NA-21 for type 2 and models NA-60 and NA-61 for type 1. Models NA-21 and NA-61 have function of impulse measurement. The features common to the four are (1) wide-range meter scale of 25 dB, (2) true rms detector having the capability for signals of crest factor 10 or more, (3) single-knob attenuater control (no dual knob attenuator), and (4) low-noise air condenser microphone (NA-20 and NA-21: 1 in., NA-60 and NA-61: 12 in.) As their versatile options, available are 1/1-octave filter unit, 1/3-octave filter unit, digital unit, and Leq unit. These are all as small as can be coupled directly to the back of a sound level meter. The 1/1- and 1/3-octave filter units work automatically synchronizing to Rion level recorder model LR-04. The digital unit displays in digits Tact-max level of 1 or 5 s and Max level. The Leq unit measures Leq of continuous and 5 s Tact-max mode and gives digital display of either.
Sound and vibration level recorders for field use
Authors: Ono Itsuo , Kaji Yoshiaki , Koshiroi Toshiaki
Published: October 2005

Level recorders are widely used to measure the wide range analog level of noise and vibration. The conventional level recorder is sometimes inconvenient for the field measuring because of its size. With respect to the dynamic characteristics, this type recorder basically differs from the sound level meter conforming to ANSI and IEC standards. Especially in case of short duration signal input, there is large difference between them. The main reason is that the pen of the level recorder responds to the input at a constant speed, while the needle of a sound level meter deflects exponenially. The two newly developed level recorders have the pen response characteristics coinciding with the indication of a sound level meter, and is very convenient for use in the field accompanying a sound level meter because of its internal battery operation, smaller size, and lighter weight. One of these is specialized for the level recording adopting the dc servo mechanism, the other is for level and waveform recording adopting the high-speed response multi-pin-head recording system.
Study of the noise and ground vibration caused by factory machines
Authors: Takatsu M.
Published: October 2005

The noise and vibration caused by hammer and press machines, etc., were investigated for the following: (1) the relation between the nominal power of hammer or crank-press machines and the noise or ground vibration caused by them, (2) the vibration reducing effect of various means of controlling vibration, (3) the frequency analysis of ground vibration, and (4) the relation between vibration level and vibration velocity. The following results were obtained from investigation(1):

(a) the level of ground vibration caused by drop forging machines, Lv = 11.6 logP + 67, where Lv is the 10 m apart from its source in decibel vibration level and P is the nominal power of machine in tons;

(b) noise level caused by drop forging machines, L(A) = 11 logP + 108, where L(A) is the A-weighted noise level 5 m apart from its source in dBA;

(c) the level of ground vibration caused by crank-press machines, Lv = 25 logP + 4; and

(d) noise level caused by crank-press machines, L(A) = 5 logP + 81. For other items the similar results were obtained.
Structure/air noise power ratio spectra of machine casings
Authors: Thorpe Howard A.
Published: October 2005

A formula for approximating these ratio spectra has been developed as part of Rohr's surface-effects ship-noise prediction methodology. These spectra are used as multipliers of measured or predicted aero-noise power spectra (in watts) of bare machine casings to predict the corresponding available machine structurenoise true power spectrum. The latter rarely is available. The formula developed for this ratio R is R = (1.5/c)(ρs/ρ)t(ρ + 300) where c and ρ are, respectively, speed of sound in and density of the fluid medium surrounding the casing, ρs is casing material density, t is casing thickness and ρ is frequency in Hertz. Units consistent with the dimensionless nature of R must be used. Underlying idealized theory and results will be sketched. Also, rationale for moderately adjusting constants of theoretical results on empirical grounds will be sketched. Adjustment of the initial constant is based on results of a relevant Rohr test/analysis program. The second constant is based on a Rohr study of compartment noise prediction validity involving a tested ship. [Work supported by U.S. Navy, NAVSEA, PMS304.]
Polyspectral analysis of rotating-machine noise and its application
Authors: Sasaki K. , Sato T. , Kano M.
Published: October 2005

The effectiveness of bispectral analysis of machine noises was shown as the possibility of detecting vary faint change of machine conditions [T. Sato, K. Sasaki, and Y. Nakamura, J. Acoust. Soc. Am. 62, 382–387 (1977)] and as passive imaging of sound sources [K. Sasaki, T. Sato, and Y. Nakamura, IEEE Trans. Son. Ultrason. SU-24, 193–200 (1977)]. This paper presents a comprehensive discussion about the noises from rotating machine from a viewpoint of the polyspectral characteristics, and a method of simulating these noises. They are characterized as a non-Gaussian random signal with dominant frequency components, which are harmonically related one another with randomly disturbed phase relations depending on the machine conditions. First, statistical properties of these noises are examined closely. Then, a concrete construction of a new synthesizer of these noises, which uses sinusoidal oscillators, Gaussian noise sources, and FM modulators, is shown. The synthesized gear-train noises show the effectiveness of the device as a simulator of noises under the transient states of the machine conditions, and the synthesizer may be useful for developing the optimal detecting method of the machine-failures.
Noise generation in FC centrifugal fans
Authors: Swim W. B. , Raj D.
Published: October 2005

Sources of broadband noise in FC (forward curved blades) centrifugal fans were studied experimentally using a 0.28-m-diameter fan. Strong tangential and axial gradients of mean velocity and static pressure were found in the housing. Very large variations in velocity and velocity fluctuations occurred across the blade passages, from the suction surface to the adjacent pressure surface. Highly separated flow in the blade passages produced a jet-wake flow pattern with large velocity fluctuations leaving the blades. Measurements on a narrow rotor (0.09 width-to-diameter ratio) mounted in a radial diffuser allowed the rotor only noise to be separated from the noise of the complete fan. Both the inlet and discharge rotor noise showed a continuous reduction in level with flow from maximum flow to the stall region. A miniature microphone mounted at various points on the blade surfaces showed a large increase in pressure fluctuations from the leading to the trailing edge of the blades. The fluctuations on the suction surface were much stronger than those on the pressure surface. Several high-frequency spikes were noted in the pressure surface spectrum. Recommendations for new blade shapes and housing configurations are proposed to reduce the unsteady flows and the related broadband noise.
A comparison of several theoretical noise abatement prediction methods for pipe lagging
Authors: Hale M. E.
Published: October 2005

With the increased emphasis on process and power plant noise control in recent years, various noise abatement techniques have been developed by theory and experiment. Among these has been the use of acoustical materials for wrapping or lagging noisy piping and equipment. Several prediction theories have been reported over the past few years to allow for the selection a priori of pipe lagging material dimensions and properties in order to reach predetermined noise reduction goals. A comparison of these prediction methods is undertaken using a variety of material dimensions and properties. These results are then compared with experimental data taken under controlled and consistent conditions. Practical advantages and deficiencies in the prediction methods are discussed.
Overview of noise from built-in equipment—lamp ballast to cooling tower—in American residences
Authors: McKay R. L.
Published: October 2005

On average, most authorities writing in the acoustical literature over the past 30 years have recommended relatively quiet criteria for noise in single- and multifamily residences. Typical recommendations are NC-25 or 35 dBA or Ldn = 40 dB. These different metrics amount to nearly the same goal. A recent study shows that “self” or interior equipment sources of the typical American residence exceed the above Ldn criterion by about 20 dB. The study also shows that typical equipment noise transmitted from apartment “neighbor” sources may meet the same criterion comfortably or exceed it by about 10 dB, depending on building design. Self and neighbor noise ranging from ±5 to 10 dB about “typical” are common. A general description of the study and its conclusions will be presented.
Effect of acoustic-cue redundancy of perception of stop-vowel syllables by language-delayed children
Authors: Stark Rachel , Tallal Paula
Published: October 2005

Previous studies demonstrated that language-delayed children have difficulty processing speech signals (such as stop-vowel syllables) which incorporate brief-duration acoustic cues [P. Tallal and M. Piercy, Neuropsychol. 12, 83–93 (1974)]. The present study was designed to determine whether the presence of multiple cues to the place feature in stop-vowel syllables would make a speech processing task more or less difficult for language-delayed children. Five- through eight-year-old language-delayed and normal children were trained to respond nonverbally to three pairs of syllables. The three pairs were phonologically the same /ba/ and /da/), but the pairs differed in the number of acoustic cues present. Pairs 1 and 2 were synthesized with two and three formants, respectively. Pair 3 was produced naturally (with multiple cues). The normal children's performance did not change significantly from one pair to another. All syllables were 250 ms in duration with 40-ms formant transitions. However, the language-delayed children's performance was significantly below normal for the two-formant ba/da pair (p < 0.001), for the three-formant ba/da pair score differences were less highly significant (p < 0.01), and for the real-speech pair there was no significant difference between groups. These results suggest that acoustic redundancy aids language-delayed children in responding to rapidly changing portions of the speech signal. [Work supported by NINCDS.]
The relationship between speech perception and speech production in children who substitute /t/ or /d/ for /s/
Authors: Dorman M. F. , Ausberger C. , Bailey P. , Raphael L. J.
Published: October 2005

Children who substitute /t/ or /d/ for /s/ in their speech production were asked to identify stimuli drawn from along a friction duration continuum (/so-to/) and a VOT continuum (/to-do/). Approximately one-half of the children identified the stimuli from both continua normally. However, the others identified the /s/ stimuli as /t/ or /d/. Identification of the VOT stimuli was normal. We conclude that at least some children with “functional” articulation disorders are impaired in their ability to identify the sounds they misarticulate. [Research supported by NICDH HD10994.]
Morphological boundaries and the timing of stressed vowels produced by profoundly hearing-impaired adults
Authors: Metz Dale E.
Published: October 2005

Stressed vowel duration is decreased when a derivational suffix is added to a base word and/or the voicing characteristic of the following consonant is altered. These effects were studied in ten normal-hearing and ten profoundly hearing-impaired adults. Each subject read 108 target words imbedded in sentences. The target words were constructed from nine CVC base words by adding a derivational suffix and/or changing the voicing characteristic of the consonant following the vowel. Vowel-duration measurements were made from a digitized oscillographic trace of the speech wave. Results indicate that the hearing-impaired adults do not observe normal vowel duration recoding, and the observed patterns of vowel duration recoding are highly consistent and idiosyncratic. Four hearing-impaired subjects consistently increased rather than decreased the duration of the stressed vowel when a derivational suffix was added to the base word. These results are discussed relative to the nature of the articulatory program used by some profoundly hearing impaired adults and its impact on speech intelligibility. [Supported by HEW.]
Identification of synthetic speech stimuli by hearing-impaired subjects
Authors: Yokkaichi Akira , Fujisaki Hiroya
Published: October 2005

Identification tests of synthetic speech stimuli can provide a more direct and accurate estimate of the impairment of speech perception in hearing-impaired subjects than those provided by the pure-tone audiometry and discrimination tests using nonspeech stimuli [H. Fujisaki et al., Ann. Rep. Eng. Res. Inst., Fac. Eng., Univ. Tokyo 28, 74–79 (1968)]. The present study utilizes synthetic speech sounds for measuring the accuracy of identification for stationary vowels, a semivowel or a liquid, and voiced stop consonants, and compares the performances of hearing-impaired subjects with medium-to-severe hearing losses to those of normal subjects. The difference in the identification accuracy between normal and hearing-impaired subjects is found to increase as the stimuli become less stationary. While in normal subjects no significant differences are found among identification accuracy for the three kinds of stimuli, a marked deterioration is observed in hearing-impaired subjects for less stationary stimuli. A comparison of the identification accuracy and the articulation score also reveals that the former is more sensitive than the latter as a measure of speech perception.
The effect of deafness on the generation of voice
Authors: Monsen R. B. , Engebretson A. M. , Vemula N. R.
Published: October 2005

The glottal source characteristics of 20 hearing-impaired adolescents were investigated with a reflectionless tube [R. B. Monsen and A. M. Engebretson, J. Acoust. Soc. Am. 62, 981–993 (1977)]. Speakers phonated a neutral vowel in normal and soft voice and in polysyllabic words with primary stress on one syllable. These data were analyzed and compared with data from normal male and female adults and with glottal waves generated by the Flanagan-Ishizaka two-mass model of vocal-fold vibration. It was found that (1) the glottal pulse produced by the deaf subjects, when considered as an isolated entity, is comparable to that of normal-hearing speakers, although certain phonation abnormalities, such as diplophonia and creaky voice, occur quite commonly among the deaf subjects; and (2) the change of the glottal source over time, as controlled by the interaction of vocal-fold tension and subglottal air pressure, is a primary deviant factor for many of the deaf speakers, and in particular the use of vocal-fold tension as a frequency changing mechanism seems impaired by the subjects' deafness. [Supported by NINCDS Grant 03856.]
Scaling the perceptual quality of pathological voice by the use of synthetic speech
Authors: Imaizumi S. , Hiki S.
Published: October 2005

In our previous study on the computer analysis of pathological voice, it was shown that acoustical parameters such as the degree of fluctuation in the fundamental frequency, amplitude, and richness of harmonic components observed in sustained utterances of vowels were useful for differentiating among diseases affecting the voice [S. Hiki et al., J. Acoust. Soc. Am. 58, S111(A) (1975)]. It was also ascertained by sound spectrographic analysis that the amount of the noise component in the various frequency ranges and the characteristics of the rise and fall of utterances of vowels were of significant value in differentiating pathological voice from normal voice, and also in differentiating the voice resulting from cancer from that of polyp, nodule and recurrent nerve paralysis [S. Hiki et al., J. Acoust. Soc. Am. 63, S86(A) (1978)]. In this paper, the relationship among these acoustical parameters and the psychoacoustic factors obtained by a subjective discrimination test of pathological voices was investigated, and, based on the results, a scale for the perceptual judgment of the quality of pathological voice was made by use of synthetic speech. [Work supported by Ministry of Education, Japan.]
Features extracted from articulation errors of young children
Authors: Singh S. , Hayden M. E. , Toombs M.
Published: October 2005

The articulation errors of 797 3- to 7-year-old speech disordered children were analyzed using a multidimensional analysis technique (INDSCAL) and a hierarchical clustering scheme (HCS). 462 of these children had primarily an articulation disorder and 335 had primarily a language problem. Each child was evaluated using a standard articulation test, and individual confusion matrices were constructed. For each disability pooled matrices were computed separately for each of the ages by sex. The ten matrices involving articulation disorders and the ten involving language disorders were input separately into both INDSCAL and HCS. The results of the INDSCAL analyses revealed that the predominant features for both disabilities were voicing, sonorancy, and front place. In addition, the group (subject) plots denoting age and sex did not reveal marked differences in feature weights due to these variables. However, the INDSCAL results revealed an impressive tendency toward grouping of phonemes by minimal pairs according to one feature or another. This output suggested the need for cluster analyses to further reveal feature usage. The features determined by these analyses were compatible with those retrieved previously in speech perception research.
Learning/adjustment effects in intelligibility testing
Authors: Bauer Benjamin B. , Baumzweiger-Bauer William , Milner Paul
Published: October 2005

A PB50 test procedure especially formatted for time saving (without carrier sentence) was used in 1974/75 to measure the intelligibility quotient of Satellite Communications Modems. Tests performed within 1–2, 3–4, and 5–6 months after the start of program were repeated by the same team in 1977. Interesting learning/adjustment effects were observed. It appears that the utilization of an unfamiliar PB50 speaker/procedure test sequence may require a 24-session-hours learning period before stability is achieved. [This program was supported in part by the U.S. Department of Transportation.]
Piezoelectricity of polymer films
Authors: Wada Y. , Hayakawa R. , Namiki K.
Published: October 2005

Origins of piezoelectricity of polymer films are classified into three: (a) internal strain, (b) strain dependence of spontaneous polarization, and (c) embedded charges coupled with mechanical and/or dielectric heterogeneity. Recent work on piezoelectricity of the polyvinylidene fluoride electret, which arises from mechanism (b) and/or (c), is briefly reviewed. A molecular theory of piezoelectricity of uniaxially oriented α-helical polypeptide [mechanism (a)] is described, in which the fluctuation formalism of piezoelectric constant is employed, enabling us to analyse the piezoelectricity on the basis of lattice dynamics taking into account microscopic parameters of structure and the force field of the polymer. The theory gives a satisfactory agreement with experiment in piezoelectric constant. A new technique for simultaneous measurement of spectra of the complex piezoelectric constant in a wide frequency range (0.003–30 Hz) has been developed, using digital data processing. The principle of the technique is described, along with some illustrative results.
Impulse response studies of piezoelectric polymer receivers
Authors: Carome E. F. , Harris G. R. , de Reggi A. S.
Published: October 2005

Various types of ultrasonic detectors for use in liquids over the frequency range 0.5–10 MHz are being constructed employing thinfilm piezoelectric polymers. These include small-diameter probes, linear elements, annular rings, and other configurations. Their response characteristics are being evaluated using acoustic impulse techniques. Experimental data will be presented that indicate the possibility of their use as broadband nonintrusive (i.e., acoustically transparent) detectors of ultrasound in water and other liquids. [Work suggested in part by DNR.]
Design principle of piezoelectric polymer transducers
Authors: Tamura M. , Iwama K.
Published: October 2005

Based on the model proposed by Edelman and de Reggi, simple fundamental relations of a sector form electroacoustic transducer with piezoelectric polymer diaphragm are derived. Calculated values of the compliance of the vibrating system are mainly controlled by the bulk modulus of the polyurethane foam backing. As an example, the sensitivity of the piezoelectric polymer headphone with an artificial ear B&K type 4153) is calculated under stiffness control frequency region. Furthermore, a push-pull-type piezoelectric polymer headphone is also studied in order to improve the sensitivity.
Piezoelectric polymer cylindrical hydrophone
Authors: Kilpatrick J. F.
Published: October 2005

An electroacoustic transducer which uses polyvinylidene fluoride (PVF2) as the piezoelectric element is investigated for its suitability as an acceleration insensitive hydrophone. The fundamental construction concept involves attaching concentric layers of PVF2 to a mechanically compatible end-capped cylinder. An expression for the electroacoustic sensitivity is developed and compared to measured acoustic data for a variety of hydrophone configurations. The axial acceleration sensitivity is measured and compared to one type of piezoelectric ceramic hydrophone.
An overview of the effects of noise on outdoor living
Authors: Peppin Richard J. , Rodman Charles W.
Published: October 2005

“Outdoor living” suggests voluntary exposure to weather and other stimuli, among them noise. The effects of noise on outdoor living are functions of societal factors, the purposes of being outdoors and, of course, the intensity, quality, and source of the noise. This paper discusses some of the concepts involved in relating noise to outdoor living, a brief history of the subject, and current research as reflected by the papers presented at the May 1978 ASTM Community Noise Symposium, as well as by other sources. Included are comments on community noise impact on hearing, human response to transportation noise, and speech interference and community annoyance.
Noise impact in modern Hawaii
Authors: Darby Ronald A.
Published: October 2005

This paper presents an overview of noise impact considerations in modern Hawaii, emphasizing those which are different from most mainland situations. The favorable year-round climate encourages outdoor recreation in public parks and the natural ventilation of residential and school buildings. However, this lack of closure often causes the noise from modern transportation systems to be excessive. Also, because of limited useable land, the high density of open housing often causes problems with acoustical privacy. Examples of the variation in freeway traffic noise with height in an “open” high-rise building will be shown. The high background noise levels created by the tradewinds in certain tropical foliage will be cited and examples shown of use as an acceptable masking noise. Likewise, the use of surf noise in planning deluxe condominium complexes will be cited. Two unique transportation noise sources will be discussed: 24-h sugar cane hauling operations and gas-turbine-powered interisland hydrofoils. Noise-abatement efforts at Honolulu International Airport will be cited, including the effectiveness of a new runway built on an ocean reef and a fixed, 15-sensor noise-monitoring system with a unique feature to log aircraft type automatically. Some noise problems related to the tourist industry will be discussed, e.g., the containment of entertainment sounds, tour bus noise, and hotel mechanical equipment noise affecting naturally ventilated homes.
An investigation of Leq, L10, and L50 in relation to loudness
Authors: Namba S. , Kuwano S. , Kato T.
Published: October 2005

Two experiments were conducted in order to make clear the propriety of Leq, L10, and L50 as the measure of traffic noise in relation to subjective judgment. Though these measures are often used, it has not yet been decided which is more suitable. In experiment 1, pink noise was used as stimuli, the level of which was changed simulating road traffic noise so that the values of Leq, L10, and L50 might be different. In experiment 2, seven kinds of traffic noises were used. Loudness of these stimuli were obtained by the method of magnitude estimation and the method of subject adjustment. As a result, Leq was found to be the most appropriate measure, showing the highest correlation with subjective judgment.
Why and how citizens react: The record of a grass roots organization
Authors: Hayes Joan
Published: October 2005

Citizen organizations on noise have sprung up … and disappeared. One shows staying power. In its ninth year it is the only large successful grass roots organization in the United States working to reduce noise. Citizens Against Noise (CAN) of Hawaii has passed the 1000 mark and continues to grow. It tackles all noise problems, except those in the work place. It has become an EPA resource. It is effective with Congress. Citizens Against Noise credits its success to early recognition that the individual could not succeed in reducing noise, but an organization could. Second, it has always emphasized the fact that if people learn what noise really does to their health they will no longer feel hobbled because “only an annoyance” is the source of their distress. A Noise Hot Line serving some 40 “clients” a week is a key CAN service. Its publications, public relations, and lobbying are basic to its success. Most of all it takes hours and hours of volunteer effort.
The nationwide impact of various noise sources
Authors: Eldred K. M. , Simpson M. A.
Published: October 2005

In this paper we present estimates made for the Environmental Protection Agency by BBN and others of the nationwide exposure of people to the noise from several types of mechanical noise sources, including motor vehicles, aircraft, construction machinery, rail vehicles, and industrial machinery. These estimates are given in terms of the number of people exposed to various day-night sound levels for sources which may cause activity interference/annoyance outdoors or within buildings, and in terms of the number of people exposed to various 8-h equivalent sound levels for sources which may cause hearing loss for operators and others nearby. From these distributions of population versus noise level, the nationwide impact of each source is estimated in terms of the level-weighted population. In addition, the evolution of these exposure and impact estimates is traced from the Title IV “Report to the President and Congress on Noise” to the present. [Work supported by EPA.]