bluuebunny/crossref_metadata_2025 huggingface dataset:
Intensity of guitar playing as a function of auditory feedback
Authors: Johnson C. J. , Pick H. L. , Garber S. F. , Siegel G. M.
Published: October 2005

The intensity of the signal produced when subjects played an electric guitar was measured as auditory feedback was attenuated or amplified at seven sidetone levels varying in 10 dB steps around a comfortable listening level. The sidetone signal was presented in quiet (experiment I) and in the presence of several levels of white noise (experiment II). Subjects demonstrated a sidetone amplification effect, playing with decreasing intensity across increasing levels of the sidetone guitar signal, as well as a Lombard effect, playing with increasing intensity across increasing levels of noise. The similarity of these results to those found previously for speech [G. M. Siegel and H. L. Pick, Jr., J. Acoust. Soc. Am. 56, 1618–1624 (1974)] suggests that guitar playing can be a useful analogue for the function of auditory feedback in speech production. Unlike previous findings for speech, the sidetone amplification effect was not potentiated by masking, consistent with an hypothesis that potentiation in speech is attributable to interference with bone conduction caused by the masking noise. [Work supported by NSF and NICHD.]
Perception of voice-onset time by Spanish-learning infants
Authors: Eilers Rebecca E.
Published: October 2005

Individual data were obtained from normal six-month-old Spanish-learning infants on four pairs of synthetic labial stops differentiable on the basis of voice onset time. All infants were presented with the pairs [pha] (+70) versus [pha] (+40), [pha] (+40) versus [pa] (+10), [pa] (+10) versus [ba] (−20), and [ba] (−20) versus [ba] (−50). Discrimination was assessed for each infant on each pair using the VRISD (visually reinforced infant speech discrimination) paradigm. Spanish-speaking adult discrimination of these pairs was also assessed. Infants presented two main patterns of discrimination: some discriminated either both the pairs +40 versus +10 and +10 versus −20 and failed to discriminate the other two stimulus pairs, and others discriminated only the pair +40 versus +10. The data will be discussed in terms of models of development of speech perception. [Work supported by NICHD HD09906-03.]
Noise annoyance judgment as affected by intensity of illumination and noise spectrum
Authors: Shigehisa T. , Gunn W. J.
Published: October 2005

Annoyance judgment was made by magnitude estimation, with noise of eight spectra, under three intensities of illumination (0.25, 2.05, 12.50 fc, achromatic). Subjects were intermediates, or ambiverts, as defined on scores of a personality inventory. Two degrees of octave-band energy attenuation, four center frequencies for this attenuation, and three overall intensities constituted the noise stimuli. The prediction was that intensity of illumination and noise frequency spectrum influence annoyance judgment; each depending on the overall noise intensity. Analysis of variance showed significant results for illumination intensity and noise spectrum. Annoyance decreased at “weak” illumination with the noise of lower-frequency attenuation (centered at 800 Hz) as compared with the control noise (without attenuation) while annoyance decreased at “intermediate” illumination with noise of intermediate-frequency attenuation (centered at 1.6 kHz), and annoyance decreased at “strong” illumination with noise of higher-frequency attenuation (centered at 4 kHz). Thus, an upward shift of effective frequencies of band attenuation for annoyance reduction was evident along with an increase in illumination intensity. Results were consistent with the prediction, and degrees of energy attenuation and overall noise intensity differentiated this prediction.
Relationship between community annoyance and speech interference
Authors: Fidell Sanford
Published: October 2005

Virtually all of the variance in data on the extent of urban noise-induced annoyance in 24 American communities was predictable by stepwise regression from speech-interference information. Both the annoyance and speech-interference data were collected in the course of a National Urban Noise Survey, an EPA-sponsored study intended to examine response to non-aircraft, nonhighway noise in communities of widely varying exposure levels, population densities, and geographic areas. Neither complaint rates nor demographic factors alone were found to be usefully predictive of the extent of community annoyance.
Impulsive underwater sound from air guns
Authors: Barger James E.
Published: October 2005

The sound impulse radiated from underwater detonation of an air gun has a peaked energy spectrum, with the peak centered on the fundamental frequency of air-bubble oscillation. Measurements of the sound impulses are reported for air guns having chamber volumes extending from 120 to 1650 in.3, chamber pressures extending from 1000 to 4000 psi, and detonation depths extending from 50 to 1400 ft. For each combination of parameters, the dominant contribution to sound energy is made by frequency components associated with the fundamental bubble oscillation frequency. Values are presented for the sound energy source levels, the fundamental frequencies, and the bandwidths of sound impulses covering the entire range of measurement variables. The fundamental frequency of air gun impulses is not found to depend upon depth and upon initial stored energy in the same way that that from impulse explosives does. Also unlike from impulse explosives, the radiated sound energy depends significantly on depth, being approximately proportional to the inverse-square power of depth. Some hypotheses are given to explain the differences between air gun and explosive sound impulses. [Research sponsored by DARPA.]
Increased tumor radiosensitivity by ultrasonic heating
Authors: Witcofski R. L. , Kremkau F. W.
Published: October 2005

Hyperthermia has been reported to reduce the amount of radiation required to locally control transplanted tumors. We have previously reported that ultrasound (US) treatment (1.9 MHz cw, 1.5 W/cm2 SA in a water bath for 15 min) either before or after x irradiation had no effect on local tumor control (TCD50) of subcutaneously implanted mammary tumors (MT), but US treatment following x ray reduced the TCD50 of the S-180 sarcoma (S-180) by 38%. We now report that US treatment prior to x ray produces statistically the same reduction (41%). Sound alone had no effect on either tumor or the skin. Skin damage was more severe with US before x irradiation than after. Water bath heating (44.5 °C for 15 min) after irradiation reduced the TCD50 of the MT by 22% and the S-180 by 37%. The S-180 results support a thermal mechanism of action for the TCD50 reduction by US. [This investigation was supported by Grant number CA17581, awarded by the National Cancer Institute, DHEW.]
Loudness scaling in rats and chinchillas
Authors: Pierrel-Sorrentino R. , Raslear T. G.
Published: October 2005

Rats and chinchillas were food rewarded for lever pressing in the presence of one of two alternating sound intensities of a 4000-Hz tone. Discrimination accuracy was indexed by percentage of presses made to the rewarded intensity, food-availability cues eliminated. Stimulus intensity pairs yielding equivalent discrimination performance were used to define equal-loudness differences. Six groups of rats were each trained on a different intensity pair. Equivalent performances at a high level of discrimination accuracy were obtained for three groups, whereas, behavioral matching occurred across the other three groups but showed a considerably lower discrimination index. Chinchillas, similarly trained, demonstrated behavioral matching at high, medium, and low discriminability levels. The various intensity pairs yielding the same discrimination indices differed when their sound-pressure-level separations were expressed in decibels but were similar (within species) when stated in loudness units calculated from a power function with SPL referenced at 20 μN/m2. For rats the exponent is 0.35, and for chinchillas, it is 0.25. This relates the growth of loudness to intensity in accord with Stevens' power law. [Work supported by NINDS.]
Right-ear advantage for voicing in subjects left-ear dominant for pure tones
Authors: Divenyi Pierre L. , Efron Robert
Published: October 2005

It has been reported [Efron and Yund, J. Acoust. Soc. Am. 59, 889–898 (1976)] that the relative salience of the two pitch components of a dichotically presented pair of tones is seldom equal: The pitch mixture is dominated by the right-ear tone for some listeners and by the left-ear tone for an equal number of other listeners. This spectrally related perceptual asymmetry was called ear dominance (ED) and was found to be independent of the well-known right-ear advantage (REA) observed for dichotically presented speech sounds. The present experiments attempted to isolate those components of REA which may derive from ED. Five subjects, left-ear dominant for tones, were tested for their ear advantage for pairs of dichotic speech sounds in a 2AFC paradigm. The synthesized stimuli were vowel pairs (differing in tongue height and/or front-back position) or CV pairs (differing either in voicing or in place of articulation). One subject displayed a left-ear advantage for all stimuli. The four other subjects retained their left ED for all features that represent only a spectral difference (vowel features and place of articulation), whereas they acquired a REA for voicing, i.e, for the feature which is primarily temporal. [Supported by the VA.]
A word advantage in phoneme boundary experiments
Authors: Ganong William F.
Published: October 2005

This study investigated one aspect of the way people integrate acoustic information derived from the speech signal with linguistic knowledge. Acoustic continua between words and nonwords were constructed, and subjects' phonetic categorizations of the stimuli were examined for a bias toward phonetic renderings which make words. Seven pairs of voice onset time continua were synthesized. For one continuum of each pair, the voiced, but not the voiceless end of the continuum was a word (e.g., “gift-kift”), and vice versa for the other continuum (e.g.) “giss-kiss”). First, these stimuli were presented in random order for phonetic categorization of the first segment of each stimulus. Those subjects who correctly identified the endpoints of the continua in a second whole-syllable identification condition showed, in the first condition, a clear and consistent bias toward phonetic categorizations which made words. All 15 of the subjects and all seven of the continua showed this bias. More detailed examination of the phonetic identification curves shows that this bias must arise before phonetic categorization.
On buzzing the English /b/
Authors: Lisker L.
Published: October 2005

The status of closure voicing as a necessary and/or sufficient property of the /bdg/ phonemes of American English has not yet been conclusively determined. Initially it is well established that glottal pulsing before release is not an essential property of the class; in fact it is quite normal for /bdg/ in this context to be voiceless stops, technically speaking. Medially and finally, too, the role of glottal pulsing during closure is not entirely clear, perhaps because discussion has more often centered on the role of closure duration and the duration of a preceding vowel as determinants of stop labeling behavior. Evidence from experiments in the perception of edited natural speech indicates that the presence of closure buzz is a strong cue to /bdg/ in medial position, but that its absence does not invariably trigger “ptk” responses. For a word token in which presence/absence of closure buzz produced a shift in phoneme labeling, the effect of varying the intensity and within-closure duration of the buzz was determined. Results suggest that closure buzz must be attenuated at least 12 dB for it to be no longer a decisive cue to /bdg/, but that at a naturally produced intensity it may fill as much as two-thirds the duration of a long closure (140 ms) without eliciting predominantly "bdg" responses. [Work supported by NICHD.]
Influence of spectral and temporal properties of vocalic environment on silence as a cue distinguishing single intervocalic stop consonants from stop clusters and geminates
Authors: Repp Bruno H.
Published: October 2005

The amount of intervocalic silence needed to perceive two different stop consonants in stimuli of the type /V1b−gV2/(type 1 boundary), and two identical stops in stimuli of the type /V1b−bV2/ (type 2 boundary), was determined as a function of different vowel contexts (V1, V2 = /a/, /i/, /u/) and of different durations of the initial and final vowels (120, 180, and 240 ms). It was predicted that changes in the vowels, and thus in the extent of the formant transitions into and/or out of the closure period, would affect type 1 boundaries more than type 2 boundaries. On the other hand, changes in vowel duration, which effectively change the perceived speaking rate, were expected to affect type 2 boundaries more than type 1 boundaries. Preliminary data tend to confirm these hypotheses, and thus support the view that type 1 and type 2 boundaries reflect temporal integration at different levels of processing. [Work supported by NICHD.]
Formant transition place cues of intervocalic fricatives
Authors: McCasland George P.
Published: October 2005

The noise of intervocalic /f,θ,s,∫/ in recorded spoken words having stressed initial vowels of similar intensity was replaced by splicing-in /s/ or /∫/ noise at various intensities equal to and below word level. Low-level noise, a segment of blank tape, yields stop impressions. In some words, the place cue of the transitions as evidenced by the stop differs from the place impression of the fricative: husi, pithy, sissie yield /p/; mushy, fishy yield /t/. At −24-dB medium strength or stronger, /s/ noise overrides the labial transition cues, and /∫/ noise overrides the alveolar transition cues, producing /s/ and /∫/ impressions, respectively. In another group of words, the transition place cue agrees with the place impression of the natural fricative: husu, lucite, hasa yield /t/; huffy yields /p/. These transition cues are 24 dB stronger in tradeoffs against conflicting noise cues than those of the first group of words: The alveolar transition cues override O-dB word level strength /∫/ noise, producing an /s/ impression; the labial cue overrides the same level /s/ noise, producing an /f/ impression.
A possible unsteady thickness noise mechanism for helicopter rotors
Authors: Hawkings D. L.
Published: October 2005

An alternative theoretical approach to the low-speed helicopter rotor noise problem is proposed. The traditional treatment of this problem is to model the situation by a system of unsteady thrust and drag dipoles. The dipole strengths are either estimated empirically, or related to the inflow distortion via an unsteady aerodynamic response analysis. An analysis is presented which suggests that an alternative model consists of a system of unsteady lift dipoles, plus a distribution of inplane quadrupoles. The strength of these quadrupoles is related directly to the product of the blade thickness and the distortion inplane velocity components. It is shown how this mechanism is likely to be the cause of the subjectively important higher harmonic rotational noise observed in or near the rotor plane. Some comparisons with experiment are presented.
Reduction of fan noise in an anechoic chamber by reducing chamber wall induced inlet flow disturbances
Authors: Dittmar J. H.
Published: October 2005

The difference between flight and ground static noise data has arisen in the past few years as a significant problem in fan jet engine noise testing. The additional noise for static testing has been attributed to inlet flow disturbances or turbulence interacting with the fan rotor. In an attempt to determine a possible source of inflow disturbances entering fans tested in the Lewis Research Center anechoic chamber the inflow field was studied using potential flow analyses. These potential flow calculations indicated that there was substantial flow over the wall directly behind the fan inlet. This flow near the wall anechoic wedges could produce significant inflow disturbances. Fan noise tests were run with various extensions added to the fan inlet ducting to move the inlet away from this back wall and thereby reduce the inlet flow disturbances. Significant noise reductions were observed with increased inlet length. Over 5-dB reduction of the blade passage tone sound power level was observed between the shortest and longest inlet at 90% fan speed and the first overtone was reduced 9 dB. High-frequency reductions in the broadband noise were also observed.
Directional spectral spreading randomly inhomogeneous media
Authors: McCoy J. J. , Beran M. J.
Published: October 2005

One of the principal consequences of a stochastic volume scattering is a redirection of the energy flux in an acoustic signal. A theory for predicting this redirection is formulated in terms of an averaged directional spectral density. In this paper we consider three specific volume scatter models. One is originally presented here. A second, termed a quasi-isotropic model, is obtained from the first upon making an additional assumption that restricts the allowable degree of anisotropy of the scattering mechanism. This second model, sometimes referred to as a Markov approximation, is identified with one originally developed in the optics literature. The third model, termed highly anisotropic, is likewise obtained from the first upon making a different additional assumption from that which led to the quasi-isotropic model. This third model is identified with one presented by the authors [J. Math. Phys. 17, 1186–1189 (1976)] specifically for long-range (≲500 km) and low-frequency (≲100 Hz) ocean acoustic experiments. We discuss differences in the algebraic structure of the models and in numerical differences for some selected conditions.
Surface reverberation measurements in Dabob Bay and the open ocean
Authors: Lilly J. G. , McConnell S. O.
Published: October 2005

Surface backscatter measurements at low grazing angles have been conducted from stable platforms in deep water in the 10–60-kHz frequency region. Measurements in Dabob Bay utilized a buoy system suspended above the bottom (600 ft) by a 3-point moor. The open ocean measurements were conducted off the southern California coast on the floating instrument platform (FLIP). Both platforms utilized a multibeam acoustic lens as the receiver. Results show the surface backscattering strength to be independent of frequency, rms wave height, and azimuth, but a strong function of wind speed. The power spectra exhibit a strong dependence upon rms wave height and azimuth, but are relatively insensitive to grazing angle and wind speed. A physical model which suggests that the small-scale ripple is the primary source of surface reverberation will also be presented. [Work supported by the Naval Sea Systems Command under contract N00024-78-C-6018.]
Blast from out the past: A capsule chronography of explosives as underwater acoustic sources for measurements of environmental acoustic parameters—their virtues and their vices
Authors: Maples L. C. , Lauer R. B. , Herstein P. D.
Published: October 2005

The role of the explosive acoustic source in ocean science over the past three decades is described and its importance evaluated. In the beginning was the Underwater Explosives Research Laboratory at the Woods Hole Oceanographic Institution, and its impressive contributions, which led directly to the fundamental works of Robert H. Cole and David E. Weston, and the formation of the Underwater Explosions Division of the Naval Ordnance Laboratory, responsible for the definitive studies and measurements of underwater explosion processes. Selected examples are cited to illustrate applications of explosive sources in acoustic propagation and reverberation studies, acoustic attenuation-absorption investigations, and bottom loss surveys. The various types and sizes commonly used are discussed. Advantages and disadvantages are considered, with attention to generic characteristics as well as to peculiarities of particular varieties. Data processing, analysis, and interpretation problems are included, with a brief resumë of related mathematical/computer model research [Work supported by the Naval Underwater Systems Center.]
The influence of Biot's second dilatational wave on the reflection coefficient of ocean sediments
Authors: Horton C. W.
Published: October 2005

The theory of acoustic waves in a porous medium developed by Biot predicts two dilatational waves. Formulas for the reflection and transmission coefficients for normal incidence at an interface are available [J. Geertsma and D. C. Smit, Geophysics 26, 169–181 (1961)]. In the present work these formulas are extended to non-normal incidence for the special case of an interface between water and porous sediments. Energy losses associated with Biot's second dilatational wave can be significant [R. D. Stoll, Geophysics 42, 715–725 0977)]. The theory will be used to predict bottom properties that can yield anomalous reflection coefficients and to propose experiments for the study of the second sound waves. [Work supported by Naval Electronic Systems Command.]
Effects of continuous wave ultrasound on the mouse at different stages of gestation
Authors: Stolzenberg S. J. , Torbit C. A. , Edmonds P. D. , Taenzer J. C. , Nell D. P. , Madan S. M. , Marks D. O. , Pratt D. E.
Published: October 2005

At five selected stages of gestation spanning days 1 through 13, mice were exposed dorsally to continuous wave ultrasound at 2 MHz, 1 W/cm2. At 200 and 400 W s/cm2 the pregnancy rate decreased and some mortality occurred. Survivors displayed reductions in mean maternal body weight gains in excess of those due to reductions in the mean number of viable fetuses and, in agreement with O'Brien [Ultrasound Meal. 2, 531–532 (1976)], decreases in mean fetal weights at necropsy before parturition. Dose response curves were obtained for fetal weight loss. Except possibly for a decrease in survival rate of fetuses exposed to 400 W s/cm2 on days 1 and 13, none of the stages of gestation was particularly sensitive to any of the effects observed. Light and electron microscope studies of ovarian, corpora lutean, and placental tissues revealed cytoplasmic and ultrastructural disruption; mitochondria showed the greatest sensitivity. The severity of ultrastructural damage appeared to be dose related. Measurements of temperature rises in the uterus to 45°C or more indicate a thermal mechanism as one cause of these effects. [Research supported by the National Institute of General Medical Sciences, Grant No. GM 22684.]
Auditory responses in cats produced by pulsed ultrasound
Authors: Foster Kenneth R. , Wiederhold Michael L.
Published: October 2005

Auditory nerve responses and cochlear microphonics are produced in cats by pulsed 5-MHz ultrasonic energy from a transducer placed against the dura mater. The pulses must be relatively intense (∼30 W/cm2) to produce a response, but can be sufficiently brief (less than 70 μs) that the brain tissue is not observably heated. The cats apparently respond to radiation pressure transients accompanying the absorption of the ultrasound in the brain tissue. Both the amplitude and latency of the N1 neural responses to the ultrasound can be matched to those produced by relatively weak tone pips or clicks from an external source. The cochlear microphonic (CM) produced by a pulse shows a prominent ringing at 5–10 kHz in different cats; the amplitude of the N1 response exhibits a broad maximum, for constant-amplitude pulses, at pulse widths of 20–60 μs. This variation of N1 response amplitude with pulse width is similar to that of a high-pass filter with a cutoff frequency at the dominant frequency of the CM.
Psychophysical tuning curves in monkeys
Authors: Serafin John V. , Moody David B. , Stebbins William C.
Published: October 2005

Psychophysical tuning curves were obtained from three normal monkeys (Macaca nemestrina), via a simultaneous masking paradigm. Masker levels necessary to mask a test tone at 10 dB SL were determined using a positive reinforcement behavioral procedure. For each animal, curves were obtained at several test frequencies. The functions, which measure the frequency selectivity of the auditory system at various frequencies, were found to share several properties in common with physiological tuning curves recorded from single units in the eighth nerve, and thus corroborate previous results in the chinchilla [T. McGee, A. Ryan, and P. Dallos, J. Acoust. Soc. Am. 60, 1146–1150 (1976)]. Curves consisted of a very steep high-frequency portion, while on the low-frequency side a two-part function was observed. The low-frequency slope was steep near the test frequency, and became more shallow approximately ½ octave below the test frequency. In addition, sharpness of tuning, as measured by Q10 values and the slopes of the functions, increased as the test frequency increased. [Work supported by NSF grant number 015832.]
Ear dominance depends on sequential, frequency-specific interactions between tones at the two ears
Authors: Deutsch Diana
Published: October 2005

Where ear dominance effects have been demonstrated, dichotic chords composed of identical frequencies were presented in succession, such that one ear received the high tone and then the low, whilst simultaneously the other hear received the low tone and then the high. Such cords have been presented in rapid, repetitive sequence [e.g., D. Deutsch, J. Acoust. Soc. Am. 55, S18–S19(A) (1974)] or judgments were made on pairs of such chords [e.g., R. Efron and E. W. Yund, Neuropsychologia 12, 249–256 (1974)]. The present experiments compared conditions where successive dichotic chords were composed of identical frequencies (as above) and where they were composed of different frequencies. Clear ear dominance effects occurred in the former case, but none in the latter. Further, ear dominance was disrupted by the interpolation of a single tone of different frequency between members of a dichotic chord pair composed of identical frequencies. Explanations of ear dominance in terms solely of simultaneous interactions are inadequate to explain these findings. [Work supported by NIMH.]
Temporal integration of tone glides as a function of intensity
Authors: Collins M. J. , Cullen J. K. , Lizana E. A.
Published: October 2005

Temporal integration of signals composed of a linearly varying frequency component (glides) was investigated in background noise (50–2800 Hz) and in quiet. Background noise levels were 40, 60, 75, and 90 dB SPL. A subject-driven detection paradigm was employed. Previously reported results [M. J. Collins and J. K. Cullen, J. Acoust. Soc. Am. 60, S48(A) (1976)] for short-duration glides (i.e., less than 10 ms) in 60-dB background noise showed rising glides were detected at a smaller signal-to-noise ratio than falling glides. In this study, differences in detectability of short-duration rising and falling glides were shown to vary with masking level, maximizing in the 60–75-dB range. In addition, detection of short-duration falling glides and their pure-tone referents occurred at smaller signal-to-noise ratios in 90-dB noise background than in 60–75-dB noise backgrounds. These results are similar to those reported by Stephens [J. Sound Vib. 30, 109–126 (1973)] for pure tones of less than 10-ms duration. [Work supported by National Institutes of Health.]
Temporal integration of constant tones at masked auditory thresholds
Authors: Nábělek Igor V.
Published: October 2005

Masked auditory thresholds of constant tones at 0.25, 0.5, 1, 2, and 3.3 kHz produced curves with slope of −3 dB/doubling of duration around 50-ms duration, steeper curves at shorter durations (between 50 and 10 ms) and slowly leveling off curves at longer durations. At 1-s duration the curves had slopes equal to zero. Between 10 and 1000 ms the curves were approximated by an exponential function as proposed by Feldtkeller and Oettinger [Acustica 6, 481–493 (1956)] and Plomp and Bouman [J. Acoustic. Soc. Am. 31, 749–758 (1959)]. However, the Plomp and Bouman's correction for increased steepness of the curves below 50 ms was substituted by another similar correction. The exponential approximation of integration curves with correction will be compared with approximations based on other models of temporal integration.
Mandible height and syllable-final tenseness
Authors: Fujimura O. , Miller J. E.
Published: October 2005

The pellet movement data obtained by the computer-controlled x-ray microbeam system, as reported on previously [O. Fujimura, J. E. Miller, and S. Kiritani, J. Acoust. Soc. Am. 60, 64(A) (1976)], reveal considerable dependence of mandible height on the tenseness distinction of the final apical consonants. Data of three male native speakers of American English have been examined. In a comparison of /tεt/ and /tεd/, for example, the mandible takes a higher position for /t/ than for /d/ around the final closure period. Initial /t/ and /d/ do not reveal such difference in the data on the same subjects. The tendency is consistent among different speakers and phonetic contexts. In some cases, mandible height for the syllable nucleus is also affected considerably by the final tenseness. Cooperation of Dr. Shigeru Kiritani and Professor Masayuki Sawashima of the University of Tokyo is gratefully acknowledged.
Articulatory and acoustic properties of /s, z/ consonants produced by esophageal speakers
Authors: Hasegawa Akira , Christensen John M. , Fletcher Samuel G. , McCutcheon Martin J.
Published: October 2005

The objective of the present study was to identify specific articulatory maneuvers and their acoustic consequences during production of /s, z/ consonants by esophageal speakers. The consonants were embedded in CVC syllables (V = i, æ, u/) in a sentence. Information on linguapalatal contact, lip and mandible position, and speech output were collected from three fluent male alaryngeal esophageal speakers who had received no radical neck dissection. Dimensions of the anterior tongue constriction and their variations were extrapolated from the linguapalatal contact patterns and subjects' dental models. Spectra of frication noises in the frequency range up to 8 Khz were characterized by a model with a set of resonances and antiresonances. The results will be discussed with respect to known functions of speech physiology and acoustics. [Supported by NIH grant NS-11852-02 and by NIH grant RR-5349 awarded to the first author.]
The effect of timing errors on the intelligibility of deaf children's speech
Authors: Osberger M. J.
Published: October 2005

At the 93rd meeting of the Acoustical Society of America, we presented a preliminary report on a technique to correct deviant timing errors in deaf children's speech by computer processing of recorded speech samples. Timing modifications were accomplished by direct manipulation of the waveform in which whole pitch periods were deleted from steady-state portions of speech segments, leaving all other aspects of the speech unchanged. The following six-stage approximation procedure was used to correct the deviant timing patterns: (1) original, unaltered utterance, (2) correction of pauses only, (3) correction of relative timing (stressed/unstressed ratio), (4) correction of absolute syllable duration, (5) correction of relative timing and pauses, and (6) correction of absolute syllable duration and pauses. This report will present preliminary data on the changes in intelligibility that occurred as a result of the systematic timing corrections Intelligibility measures were obtained by playing the original sentences and the computer-modified versions to persons not familiar with the speech of the deaf. The measure of intelligibility was the proportion of words correctly understood by the listeners. The data showed that, on the average, intelligibility improved slightly when relative timing errors only were corrected. A decrease in intelligibility was observed for the other forms of timing modification. There were marked individual differences and the correction of deviant timing patterns was relatively more important for improving the intelligibility of some children's speech than others. [Research supported by PHS Grant NS 09252.]
More on “doubling.”
Authors: Buhr Robert
Published: October 2005

The occurrence of multiple harmonics between the harmonics of the natural f0 in modal and high registers has been described in previous work (Buhr and Keating, 1977). The present study explores the claim that such “doubling” occurs at the extreme ranges of modal register in infants and children, and that its occurrence is associated with production “instability” at these ranges. Spectral and waveform analysis tend to support this claim. Furthermore, waveform analysis of utterances in which “doubling” is occurring suggests that this instability may be inherent in the phonation of infants and children, but not in adults, except under certain circumstances. The predictability of this phenomenon will also be discussed.
The effects of palatal appliances on the speech of five-year-old children
Authors: Garber S. R. , Speidel T. M.
Published: October 2005

Forty five-year-old children were divided into two groups based upon their scores on an articulation test. Following the articulation test, children in both groups named pictures while wearing no appliance and while wearing a 1-mm-thick palatal appliance. They performed the tasks in quiet and while hearing a 90-dB-SPL speech noise. Tape recordings of the subjects were analyzed perceptually for articulation errors. Errors increased when the appliance was placed and when the noise was introduced. There was no interaction between the effects of the appliance and the noise on speech. The effects of appliances and noise on speech were similar for the two groups of subjects. The data from the present study parallel those from a previous study with adult subjects [S. R. Gather, T. M. Speidel, and L. Glass, J. Acoust. Soc. Am. 61, S7(A)( 1977)]. [Work supported by an NIDR postdoctoral fellowship awarded to S. R. Garber.]
Room acoustic requirements for the performer
Authors: Benade A. H.
Published: October 2005

Musicians make great use of early echoes of their sounds, which provide auditory feedback that is useful in monitoring tone color, articulation, tuning, playing level, and other aspects of an artistic performance. In ensemble playing the role of early echoes is even more important because of their utility in coordinating the efforts of the various performers; this is true both with or without a conductor, who at best serves only as a policy maker. Thus, without secure musical communication on stage, no hall works well for the listener even when stage-to-audience coupling is optimized (Shankland, 1977). It is also found that players and instrument makers depend on early echo information to gain an integrated view of the onset and steady-state behavior of an instrument under adjustment. Such work is difficult and untrustworthy when performed in echo-free surroundings. We need to know more about the auditory mechanisms for extraction of musically relevant data from randomly scattered spectral complexes originating from essentially coherent musical sources. It seems probable that an elaborated form of the precedence effect is involved. Emphasis will be laid on possible areas for future research on these mechanisms as they interact with various parts of the instrument-room-listener chain.
A method for measuring early-, mid-, and high-frequency patterns in concert halls
Authors: Jaffe C. , Lobb W.
Published: October 2005

The importance of receiving a sufficient number of early reflections in the mid and high frequencies in terms of qualitative symphonic listening experience was described by Beranek 15 years ago [Music. Acoustics and Architecture (Wiley, New York)]. Earlier measurement methods using tone bursts tend to smear oscillograms as time progresses and unidirectional speakers do not provide the omnidirectional characteristics of a full symphony orchestra. The method developed by the authors incorporates an N wave pulse, a dodecahedron speaker source in conjunction with a microphone mounted in a parabolic disk. Measurements taken at 30° intervals provide a graphic signature of early-, mid-, and high-frequency reflections arriving at a given location. Time, intensity, and direction of these reflections can be readily compared in existing facilities and models of new halls. The all important binaural patterns are separated from the others and graphically related to the shaping of the boundary surfaces of the hall as well as any suspended reflectors.
Ultrasound imaging for characterization of biological tissue and function
Authors: Rajagopalan Balu , Greenleaf James F. , Johnson S. A.
Published: October 2005

Quantitative images of acoustic speed distribution in excised human tissues, in excised dog myocardium, and in in vivo female breasts were obtained by ultrasound computerized tomography. The in vitro study was carried over a temperature from 20° to 40 °C. Results indicate (1) acoustic speed in human tissues (except fat) increase monotonically with temperature in this range, (2) fat shows an anomalous decrease in acoustic speed around 35 °C, (3) average acoustic speed is higher in breasts with cancer and with fibrocystic disease compared to normal breasts, and (4) acoustic speed is a function of age. The reconstruction problem in ultrasound computerized tomography is unlike its x-ray analog because of the refraction and diffraction effects. Methods to correct for the consequent degradation are discussed. The backscattering properties of in vivo myocardial tissue of dogs were studied by a high-resolution B-scanner and the potential of (renovist and indocyanine green) as ultrasound contrast agents to quantitate perfusion in the myocardium will be discussed. [Work supported by NCI-CB-64041, HV 72928, HL-07111, HL-00060, HL-00170.]
Optical determination of the transmit pulse characteristics of medical transducer arrays
Authors: Riley W. A. , Barnes R. W.
Published: October 2005

Two medical ultrasound array systems are currently being developed and evaluated within the Cerebrovascular Research Center at the Bowman Gray School of Medicine. One objective of these systems is to image intracranial and extracranial arteries and provide clinical information pertinent to atherosclerosis and other stroke-related diseases. An optical system with a bandwidth exceeding 10 MHz has been constructed to study the spatial and temporal characteristics of the wide-bandwidth pulses transmitted by 1- and 5-MHz arrays used in these systems. The optical system is based upon the optical nearfield method of Cook [J. Acoust. Soc. Am. 60, 95–99 ( 1976)] for studying ultrasonic pulse waveforms. The use of this wide-band system makes it possible to experimentally separate the transmit and receive characteristics of the arrays which could be used in a variety of transmit-receive configurations. The general process of array field formation can be experimentally studied and the beam profiles and transmitted power determined. [This work was supported by NINCDS grant NS-06655 and a grant from North Carolina United Way.]
Binaural temporal masking
Authors: Yost William A.
Published: October 2005

Masking of transient and tonal signals was studied in both diotic and dichotic temporal listening conditions. Temporal conditions of forward, backward, and combined forward-backward masking were used. Some of the variables which we have studied are the temporal separation between maskers and signal, the spectral differences between maskers and signal, and the type of dichotic stimulus configuration. Masking in dichotic conditions appears to parallel that obtained in diotic conditions when the forward- and backward-masking procedures are used. Substantial differences exist between diotic and dichotic masking in the combined forward-backward-masking procedures. A summary of these results will be provided in order to describe some of the basic relationships that exist in binaural masking when the signal and masker are not presented simultaneously. [Work supported by NSF and NIH.]
The nature of two-tone suppression revealed in forward masking
Authors: Moore Brian C. J.
Published: October 2005

The two-tone suppression effect in forward masking may be equivalent to a simple attenuation of the level of the suppressed tone. To test this we equated two maskers by determining the level of a 1-kHz tone required to mask a 1-kHz probe at 30 dB SL for the 1-kHz tone (a) alone (level L1), (b) together with a 1150-Hz tone at L1 + 20 dB. According to the simple attenuation hypothesis the 1-kHz components in these two maskers should be equivalent in their internal representation and thus equally effective as maskers. Accordingly, the probe threshold was measured as a function of probe frequency for each of the two maskers. Contrary to the predictions probe threshold was higher for the second masker when the probe frequency was less than 980 Hz. However this discrepancy may be explained by the combination tone at 850 Hz produced by the two-tone masker. An adaptive 2-AFC procedure was used throughout, with 20-ms probe tones and 300-ms maskers.
Effects of interstimulus interval on identification and discrimination of isolated vowels
Authors: Healy Alice F. , Repp Bruno H. , Crowder Robert G.
Published: October 2005

Synthetic steady-state vowels from an /i/-/I/-/ / continuum were presented in an AX discrimination task. The interval between the stimuli in a pair was either short (240 ms) or long (1920 ms), and either empty or filled with irrelevant vowel sounds. Discrimination performance was disturbed by both these manipulations, suggesting that auditory memory is subject to decay as well as to interference. In a second experiment, we predicted discrimination performance at short-unfilled and long-filled intervals from identification response to the same AX pairs. While obtained discrimination performance exceeded the predictions, this difference was equally small at the two interstimulus intervals. Identification was as much affected by interstimulus interval as discrimination: There were large contrast effects at the short-unfilled interval, but not at the long-filled interval. Implications of these results for models of categorical perception will be discussed. [Work supported by NICHD.]
Observed scattering from salt fingers produced by the two-solute method
Authors: Temple P. R. , Lambert R. B. , Letcher S. V.
Published: October 2005

Salt fingers are a mechanism of vertical transport in fluids. If a layer of warm, salty water overlies cooler, fresher water, salt fingers may form at the interface. Initiated by the difference in molecular diffusivities, a column, or finger, of downward-flowing warm, salty water has fingers of upward-flowing cooler, fresher water as nearest neighbors. More controlled experiments are accomplished in the laboratory using two solutes of different molecular diffusivities, such as sugar and salt. Since salt fingers have a characteristic horizontal dimension and align in a semiregular fashion, an interesting effect on horizontally propagating sound could exist. This study experimentally examined the relation of the angular behavior of the scattered signal to the acoustic frequency and the characteristic horizontal dimension of the salt fingers. A few frequencies between 0.77 and 13.30 MHz were investigated using separate receiving and transmitting hydrophones. Amplitude variations in the scattered signal with angular change were noted for each frequency. Utilizing concurrent salt-finger width measurements, the data proved consistent with a Bragg-type analysis at lower frequencies (acoustic wavelength same order as salt-finger wavelength). Data obtained at the higher frequencies could not be considered in the same manner.
Experimental determination of the adiabatic compressibility of liquids and solids as a function of temperature and pressure
Authors: Boles L. A. , Timme R. W. , Shelton M. R.
Published: October 2005

An experimental method for determining the adiabatic compressibility of various liquids and solids is described. A reciprocity-coupler method is utilized to measure the sensitivity of a hydrophone at 500 Hz over a temperature range 5–45 °C and a pressure range 0–100 MPa, gauge. Theory is presented which shows that the adiabatic compressibility of the coupler contents can be obtained by comparing the sensitivity measured for a material whose acoustic properties are known to that for the material in question. Experimental results are shown.
Some vascular effects of noise exposure in the chinchilla
Authors: Axelsson A. , Vertes D. , Lipscomb D. M.
Published: October 2005

Chinchillas were exposed to pink noise at levels ranging from 110 dB (for 8 h) to 125 dB (for 14 h). After a three-week survival period, the animals were terminated without anesthesia and tissues were prepared using a soft-surface preparation technique [Axelsson et al., Ann. Otol. 83, 537 (1974)]. Cochlear hair cell damage as well as vascular pathology was slight. On occasion, a vessel or vessel segment was obviously atypical, thus allowing noise-exposed animals to be differentiated from their non-noise-exposed controls. More often, however, differences between animals were more discrete and only evident through a computer analysis of the data. The specific effects of these particular noise-exposure parameters on the cochlear blood supply of the chinchilla will be discussed.
Unmasking effects produced by combination tones
Authors: Tyler Richard S. , Small Arnold M. , Abbas Paul J.
Published: October 2005

This experiment investigates some interactions between combination tones and suppression. Using a two-tone stimulus in a psychophysical forward-masking paradigm, the effective masking of the first tone (masker) on the signal can be reduced by the addition of a second tone (suppressor). We present evidence here that a combination tone, not present in the stimulus, can effectively be used as a suppressor. By comparing the threshold shift produced by the masker alone and by the masker-suppressor combinations, the amount of unmasking (or suppression) as a function of suppressor frequency was measured. Then, two higher-frequency stimuli were added to the masker, neither of which produced unmasking when presented individually. When the cubic difference tone or the difference tone produced by these two additional stimuli were of appropriate frequency, unmasking was observed. The unmasking produced by the combination tones was similar in its frequency characteristics to that of a single suppressor tone. The results suggest that both the cubic difference tone and the difference tone behave as if they were present in the stimulus.
Intensity effects in forward masking: Implications for psychophysical tuning curves
Authors: Widin Gregory P. , Viemeister Neal F.
Published: October 2005

The effects of masker intensity and masker frequency on the threshold of a 1-kHz, 20-ms probe were assessed in forward masking, with a masker-probe delay of 5 ms. In general, probe threshold is a power function of masker intensity, with an exponent considerably less than unity; the exponent and constant of proportionality depend upon masker frequency. For example, with a 1-kHz masker, a 10-dB increase in masker level increases probe threshold by only about 5 dB, over a 60-dB range of masker intensities. The nonlinear relation between probe threshold and masker intensity is consistent with the increased “selectivity” sometimes observed in forward-masked tuning curves as compared with those obtained in simultaneous masking. These data then emphasize the importance of nonlinear intensity effects, in addition to possible changes in true frequency selectivity, in determining the form of psychophysical tuning curves obtained in forward masking and their relation to those obtained in simultaneous masking. [Supported by NICHD, NINCDS.]