bluuebunny/crossref_metadata_2025 huggingface dataset:
Localization suppression and fusion measure of the precedence effect in young children
Authors: Litovsky Ruth , Godar Shelly , Yu Gongqiang
Published: September 2013

This study investigated aspects of the precedence effect (PE) known as fusion and localization dominance in children 4–5 years of age. Stimuli were three, 25-ms noise bursts (2-ms rise/fall times) with 250-ms ISI. On PE conditions the lead stimulus was presented from one of six locations in azimuth, and the lag was at 0 deg. Lead-lag delays varied from 5 to 100 ms. Localization was measured using an identification paradigm. Fusion was measured separately whereby subjects reported whether a single auditory event or two auditory events were perceived. Children reported two sounds on 75% of trials (fusion threshold) at delays ranging from 15 to 35 ms. Below fusion thresholds, the localization of the lead was similar to that of single-source stimuli. Above fusion thresholds lead localization was significantly degraded, persisting out to 100 ms. Localization of the lag was poor at all delays on which it was reported as being heard. According to these results localization dominance (difficulty localizing the lag) in children persists at greater delays than fusion, which is consistent with findings obtained in adult subjects. The range of delays over which these effects are robust in children is longer than the range observed in adults.
An evaluation of two frequency-based mechanisms for direct-to-reverberant energy ratio discrimination
Authors: Iyer Nandini , Larsen Erik , Lansing Charissa , Feng Albert
Published: September 2013

To determine the mechanism by which direct-to-reverberant energy ratio (D/R) is discriminated, a previous experiment (Larsen et al., 2003) reported JNDs at three different D/R values (−10, 0, +10 dB). Of three proposed mechanisms, the data favored a model based on detection of spectral variation of the magnitude of the source-receiver transfer function. However, a model based on detection of spectral centroid of the received signal could not be rejected conclusively. In order to determine the relative salience of spectral variance versus spectral centroid cues, the current study reports findings from two experiments. These data will be useful in the development of a general model for distance perception. D/R was fixed at 0 dB, because D/R discrimination is most acute (Larsen et al., 2003) and spectral variations are largest (Jetzt, 1979) at that ratio. In experiment one, signals (300 ms Gaussian noise; 10 ms onset/offset time) were modified such that spectral variation cues were removed by roving the compression of the spectral envelope variations. In the second experiment, spectral centroid cues were removed by using band-limited signals (300 ms Gaussian noise; 10 ms onset/offset time) and roving the center frequency. Listener sensitivity in both these experiments will be compared to model predictions.
The transmission loss through curved sandwich composite structures
Authors: Ghinet Sebastian , Atalla Noureddine , Osman Haisam
Published: September 2013

The principal aim of this work is to present a model for the transmission loss of sandwich composite cylindrical shells. The effects of membrane, bending, and transverse shearing as well as rotational inertia are considered in all of the layers composing the structure. The elastic constants of any layer are related to the orthotropic angle-ply defined as the angle of the principal directions of the layers material to the global axis of the shell. Fundamental relations are expressed using the dynamic equilibrium relations of the unit forces in the structure. The structural impedance, critical frequencies and ring frequency are computed numerically in the general case of symmetrical laminated composite shell. Their expressions are developed in a wave approach context. A general eigenvalue approach to compute the dispersion curves of such structures is presented. Using these curves, the radiation efficiency, the modal density, the group velocity an the resonant and nonresonant transmission loss are computed and used within SEA framework to predict the sound transmission loss of these structures. Comparisons with existing models and experimental data are also discussed.
Theoretical investigation of noise transmission into a finite cylinder
Authors: Li Deyu , Vipperman Jeffrey S.
Published: September 2013

A new mathematical model for characterizing noise transmission into a finite elastic cylindrical structure with application to a ChamberCore composite cylinder is presented. A plane wave obliquely impinges on the structure, the external sound field is approximated by the solution for an infinite cylinder, and the internal sound field is solved with the structural and acoustic modal interaction method. The noise reduction spectrum for characterizing noise transmission into the cylinder is defined, and the analytical model for the calculation of the noise reduction spectrum is developed. The analytical results show that the cavity resonances dominate the noise transmission into the finite cylinder, and the longitudinal acoustic modes play an important role in the noise transmission at the low frequencies. These results are matched with experimental results.
Noise control of submerged sources using close fitting enclosures
Authors: Cuschieri Joseph M.
Published: September 2013

Controlling the sound radiation from a source can be either performed at the source or in the transmission path or both. Modifications of the transmission path can be in the form of a close fitting enclosure. Simple models are available to estimate the effectiveness of the close fitting enclosure. However, if the sound source is submerged in water, the presence of the fluid within and external to the close fitting enclosure, and the type of absorption material within the enclosure, may influence the enclosure effectiveness. Modeling the fluid solely by its characteristic impedance may not lead to reasonable results. The influence of the fluid on the behavior of the close fitting enclosure should be taken into account in the modeling. Numerical results are presented that compare the insertion loss estimated using ‘‘simple’’ close fitting enclosure models to that from multi-layer theory. [Work supported by ONR.]
A viscous-acoustic boundary element formulation based on analytical-numerical matching
Authors: Bliss Donald B. , Swingle Matthew S.
Published: September 2013

Analytical-numerical matching (ANM) is an analysis scheme that combines a low-resolution global numerical solution with a high-resolution local analytical solution and a matching solution to form a uniformly valid composite solution. The application of ANM to harmonically oscillating bodies in a fluid leads to a novel reformulation of boundary element problems in acoustics and aeroacoustics. The singular kernal encountered in the integral equation is handled simply within the analytical local solution. The numerical implementation utilizes a smoothed Green’s function solution to the governing equation with a distributed source term. Because the singular behavior has been removed from the numerical aspect of the problem, the approach converges rapidly and exhibits insensitivity to node (control point) location. The method allows low-resolution numerics to be combined with analytical corrections to obtain high accuracy solutions using a robust calculation scheme. The method has recently been extended to include viscous effects within the local solution. The appropriately modified global solution remains irrotational and can be expressed in terms of a smoothed potential. Sample results are shown for radiation from plates up to high frequencies. Ongoing research on ANM BEM is described, including work to include nonlinear convection within the viscous flow effects.
The effect of emphatic stress on CV coarticulation
Authors: Modarresi Golnaz , Sussman Harvey M.
Published: September 2013

The effect of emphatic stress on CV coarticulation was investigated in the speech of one male and one female native speaker of American English using locus equation slope as a measure of CV coarticulation. Stressed real word C1V2C2 tokens where C1=/b,d,g/ and V2=/i, I, e, ε, æ, u, o, ɔ, a/ were put in carrier sentences with the, thirty, or two preceding the test word. Each sentence was read three times in a normal manner and three times with emphasis on the test token. This resulted in a total of 486 tokens per speaker (3 stop consonants * 3 V1 contexts * 9 V2 contexts *2 emphasis patterns *3 repetitions). Locus equation slopes were derived by plotting F2 onset of C1 against V2 F2 mid-vowel frequency and fitting a regression line to data points. Consonant closure duration, V2 duration, F0, and amplitude were also measured. Despite a significant increase in the acoustic correlates of emphasis, locus equation slopes remained constant as a function of emphasis and varied as a function of place of articulation. This study provides further evidence of the stability of locus equation slopes as phonetic descriptors of stop place of articulation. [Work supported by NIH.]
The Nationwide Speech Project: A multi-talker multi-dialect speech corpus
Authors: Clopper Cynthia G. , Pisoni David B.
Published: September 2013

Most research on regional phonological variation relies on field recordings of interview speech. Recent research on the perception of dialect variation by naive listeners, however, has relied on read sentence materials in order to control for phonological and lexical content and syntax. The Nationwide Speech Project corpus was designed to obtain a large amount of speech from a number of talkers representing different regional varieties of American English. Five male and five female talkers from each of six different dialect regions in the United States were recorded reading isolated words, sentences, and passages, and in conversations with the experimenter. The talkers ranged in age from 18 and 25 years old and they were all monolingual native speakers of American English. They had lived their entire life in one dialect region and both of their parents were raised in the same region. Results of an acoustic analysis of the vowel spaces of the talkers included in the Nationwide Speech Project will be presented. [Work supported by NIH.]
Formant shift in nasalization of vowels
Authors: Arai Takayuki
Published: September 2013

We measured the formant shifts of a vowel in the context of a nasal and investigated whether human perception is able to compensate for such shifts. According to the acoustic theory, nasal coupling causes a modification on the spectrum, including formant frequency shift. The first goal of this study is to confirm that the formant frequencies actually shift due to nasalization. Based on several measurements of formant frequencies of various vowels in nasal contexts, we confirmed that the first formant (F1) tends to shift in a more central direction when nasalized. In English, vowels should be perceived as the same phoneme regardless of nasalization. In other words, listeners might have the capability to compensate for such formant shifts. The second goal of this study is to eximine this compensation effect by a perceptual experiment. For stimuli, we synthesized a nonnasal vowel V0 that has the same formant frequencies as a nasalized vowel V1. A continuum was also synthesized between V0 and the nonnasalized version of V1. Results show V1 is more correctly identified than V0, which suggests the existence of the compensation effect.
Dholuo interdentals: Fricatives or affricates? Evidence from domain-initial strengthening
Authors: Degenshein Rachael , Chitoran Ioana
Published: September 2013

The manner of articulation of 〈th,dh〉 in Kenya Dholuo is described controversially in the literature. This study uses acoustic data collected from three native speakers of the same dialect to test the hypothesis that 〈th,dh〉 exhibit positional variation, in accordance with domain-initial strengthening. The prediction that 〈th,dh〉 are realized as affricates in strong position and fricatives in weak position was supported. All three speakers showed longer closure for 〈th〉 in pretonic than in non-pretonic position (F=166.833, p<0.01), and in word-initial than medial position (F=66.505, p<0.01). In line with the prediction that longer pre-voicing is indicative of a weaker closure, the pre-voicing of 〈dh〉 followed the hierarchy: Intonational Phrase (IP) medial word-medial > IP-medial word-initial > IP-initial without focus > IP-initial with focus (F=116.513, p<0.01). IP-initial 〈dh〉 and 〈d〉 had similar prevoicing duration (72.120; 72.434) suggesting that the interdental became more stoplike in this position. Furthermore, whereas it is known that vowels are longer before fricatives than before stops, the vowels before 〈th,dh〉 were not longer than those before the corresponding stops 〈t,d〉 suggesting 〈th,dh〉 are stop-like. Using both qualitative and quantitative criteria, Dholuo interdentals are best described as affricates with differences in articulation in prosodically stronger versus weaker positions.
Parametric synthesis of Korean alveolar stops
Authors: Yun Gwanhi
Published: September 2013

Korean alveolar stops were synthesized through MITalk system to evaluate the parameters. Because of the insufficiency of reliable acoustic cues to distinguish three-way Korean stops, synthesized stops were expected to lack intelligibility and naturalness. In the first synthesis, AH (amplitude of aspiration during transition from C to the following V), duration of transition, formant frequencies, bandwidths of formants, and F0 of the following vowels were employed as main parameters only at two anchor points, i.e., at the burst point and onset of the following vowel. As expected, the plain stops (33%) were not satisfactorily discriminated from tense stops (39%), and naturalness was below chance. However, the discrimination between plain/tense and aspirated stops was not so bad. Further, the intelligibility and naturalness of aspirated stops were so low. Thus, to compensate for lack of reliable parameters, two parameters were readjusted: (1) duration of AH and (2) duration of transition. The identification results showed that the longer AH and transition, the more accurate the perception of aspirated stops. Thus, it indicates that AH and duration of transition might work as a trade-off relation for the perception of aspirated stops, and so a relevant combination of parameters in SynthWork may synthesize more accurate Korean aspirated stops.
Perceptual consequences of nasal consonant ‘‘surrogates’’ in English: Implications for speech synthesis
Authors: Hertz Susan R. , Spence Isaac C. , Church Thomas F. , Goldhor Richard
Published: September 2013

Experiments indicate that non-nasal obstruents in human utterances can be replaced by ‘‘surrogate’’ segments, either produced by formant synthesis or recorded from other speakers, with virtually no change in speech quality or speaker identity [Hertz, Proc. IEEE 2002 Workshop on Speech Synthesis (2002)]. While the durational and spectral properties of the surrogate segments must be broadly appropriate to their target context, no speaker-specific tailoring is required. This paper describes follow-on experiments studying the perceptual consequences of replacing nasal consonants in human utterances with surrogate segments from different phonetic contexts, either synthesized or spoken by other speakers. These experiments indicate that the manipulated speech sounds natural when surrogate segment durations, and the formant transitions and nasalization characteristics of adjacent vowels, are appropriate. In certain contexts F0 is also perceptually salient. The spectral characteristics of surrogate nasal murmurs are often unimportant. In many cases, the perceived speech quality, phoneme identity, and speaker identity are unaffected even by a surrogate from a phoneme differing from the original. This paper highlights the perceptual results and explains their relevance to hybrid synthesis techniques that employ cross-speaker waveform concatenation and/or integrate waveform concatenation with formant synthesis. Utterances that exemplify these results will be played.
Signature of prosody in tonal realization: Evidence from Standard Chinese
Authors: Chen Yiya
Published: September 2013

It is by now widely accepted that the articulation of speech is influenced by the prosodic structure into which the utterance is organized. Furthermore, the effect of prosody on F0 realization has been shown to be mainly phonological [Beckman and Pierrehumbert (1986); Selkirk and Shen (1990)]. This paper presents data from the F0 realizations of lexical tones in Standard Chinese and shows that prosodic factors may influence the articulation of a lexical tone and induce phonetic variations in its surface F0 contours, similar to the phonetic effect of prosody on segment articulation [de Jong (1995); Keating and Foureron (1997)]. Data were elicited from four native speakers of Standard Chinese producing all four lexical tones in different tonal contexts and under various focus conditions (i.e., under focus, no focus, and post focus), with three renditions for each condition. The observed F0 variations are argued to be best analyzed as resulted from prosodically driven differences in the phonetic implementation of the lexical tonal targets, which in turn is induced by pragmatically driven differences in how distinctive an underlying tonal target should be realized. Implications of this study on the phonetic implementation of phonological tonal targets will also be discussed.
Variation of Taiwanese tones in conversation
Authors: Hsieh Pei-Yu , Tsay Jane
Published: September 2013

In laboratory research on tonal coarticulation in Taiwanese, one study [H.-B, Lin, Ph.D. dissertation, Univ. of Connecticut (1988)] reported a perseveratory effect but no anticipatory effect, while another [S.-H. Peng, J. Phonetics 25, 371–400 (1997)] found a significant anticipatory effect. Peng also found tonal variation due to prosodic positions. Unlike these previous laboratory studies, this study attempts to investigate tonal coarticulation and prosodic effects on Taiwanese tones using natural conversations from the Taiwanese Spoken Corpus (Tsay and Myers, 2004), of which 56 min of recorded conversations were analyzed. Consistent with Lin, the results showed that tone is more affected by the preceding tone than by the following tone. The slope is more influenced by the preceding tone as well. As for prosodic effects, the results confirmed Peng, showing that F0 is the lowest in utterance-final position, while in other phrase-final positions it is slightly lower than in non-phrase-final position. This study thus demonstrates the results obtained in the laboratory do indeed carry over into actual conversation.
Contrasting the effects of duration and number of syllables on the perceptual normalization of lexical tones
Authors: Ciocca Valter , Francis Alexander L. , Yau Teresa S.-K.
Published: September 2013

In tonal languages, syllabic fundamental frequency (F0) patterns (‘‘lexical tones’’) convey lexical meaning. Listeners need to relate such pitch patterns to the pitch range of a speaker (‘‘tone normalization’’) to accurately identify lexical tones. This study investigated the amount of tonal information required to perform tone normalization. A target CV syllable, perceived as either a high level, a low level, or a mid level Cantonese tone, was preceded by a four-syllable carrier sentence whose F0 was shifted (1 semitone), or not shifted. Four conditions were obtained by gating one, two, three, or four syllables from the onset of the target. Presentation rate (normal versus fast) was set such that the duration of the one, two, and three syllable conditions (normal carrier) was equal to that of the two, three, and four syllable conditions (fast carrier). Results suggest that tone normalization is largely accomplished within 250 ms or so prior to target onset, independent of the number of syllables; additional tonal information produces a relatively small increase in tone normalization. Implications for models of lexical tone normalization will be discussed. [Work supported by the RGC of the Hong Kong SAR, Project No. HKU 7193/00H.]
Tone clarity in mixed pitch/phonation type tones
Authors: Andruski Jean E.
Published: September 2013

Lexical tone identity is often determined by a complex of acoustic cues. In Green Mong, a Hmong-Mien language of Southeast Asia, a small subset of tones is characterized by phonation type in addition to pitch height, pitch contour, and duration, which characterize the remaining tones of the language. In tones that incorporate multiple cues to tonal identity, what makes a tone clear, or easy to recognize? This study examines acoustic and perceptual data to address this question. Six native speakers of Green Mong were asked to produce 132 phonological CV words in sentence context, using a conversational speaking style. Seventeen native speakers of the language were then asked to categorize three tones which have similar falling contours, but are differentiated by phonation type (breathy, creaky, and modal). Tokens that were correctly identified by 100% of the listeners were compared with tokens that were relatively poorly identified. Data indicate that the breathy- and creaky-voiced tones are less susceptible to identification errors than the modal-voiced tone. However, the clearest tokens of the three tones are also differentiated by details of pitch contour shape, and by duration. Similarities and differences between acoustic cue values for the best and worst tokens will be discussed.
Tonal production of early and late Canadian Cantonese bilinguals
Authors: So Connie K.
Published: September 2013

Previous studies show that native speakers have exhibited changes in both phonetic and phonemic characteristics in their L1 production and perception after living in an L2 community for years. Little is known if the phenomenon is also present in the tonal production of native speakers of tone languages who grew up in an English-speaking environment. This research examines both the phonetic and phonemic features of the six Cantonese tones (i.e., vowel duration, pitch contour, and tonal space) produced by two groups of adult Canadian Cantonese bilinguals: early (AOA: less than 1 year) and late (AOA: 10–13 years). The data collected were compared with those of a group of native Cantonese speakers (AOA: greater than 18 years). Analyses revealed that (i) both the early and the late bilinguals produced significantly longer vowel durations than did the comparison group, and that (ii) their pitch contours and tonal space were significantly different from those of the native speakers. In addition, the early bilinguals’ tonal productions were more deviant from the native productions than those of the late bilinguals.
Sonar image enhancement via acoustic color
Authors: Neretti Nicola , Intrator Nathan , Huynh Quyen
Published: September 2013

A novel method to enhance synthetic aperture sonar (SAS) images using the acoustic color of the returns from different targets is presented. The method enhances the SAS image using the internal absorption properties of targets in a way that enhances the differences between different types of targets (target signature). First, the algorithm detects the highlights in the sonar image as is found from the beam-formed processed image. These highlights represent edges of targets. Then the analysis is performed only at the echo returns which correspond to edges of targets. For each edge the raw data corresponding to the return from that edge is found. This data which has not yet been pulse-compressed using the pinging signal is analyzed using a detailed frequency representation. Then, the frequency representation of the pinging signal is subtracted from it so that a resulting frequency representation of the difference between the pinging signal and the returning signal is obtained. A normalization of the returned echo is performed before the subtraction to compensate for the lower energy of the returning echo. The same method can be extended to a more detailed analysis of internal structures of targets.
Comparison between ocean-acoustic fluctuations in parabolic-equation simulations and estimates from integral approximations
Authors: Flatté Stanley M. , Vera Michael D.
Published: September 2013

Line-integral approximations to the acoustic path integral have been used to estimate fluctuations due to internal waves. Approximations for the root-mean-square (rms) fluctuation and the bias of travel time, rms fluctuation in vertical arrival angle, and the spreading of the acoustic pulse out to 1000-km range are here compared to estimates from simulations that use the parabolic equation (PE). [See S. M. Flatté and M. D. Vera, J. Acoust. Soc. Am. 114, 697–706 (2003).] Integral-approximation (IA) estimates of rms travel-time fluctuations were within statistical uncertainty at 1000 km for the Slice89 profile, and in disagreement by between 20% and 60% for the Canonical profile. Bias estimates were accurate for the first few hundred kilometers of propagation, but often disagreed beyond. The PE structure functions of travel time with depth were quadratic for vertical separations of 20 m or less, in qualitative agreement with the IA prediction. Pulse spreads in the PE results were much smaller than predicted by the IA estimates. Implications of these results will be discussed. [Work supported by ONR.] a)Currently at Scripps Institution of Oceanography.
Acoustic effects from the horizontal variability spectrum of nonlinear internal waves
Authors: Reilly-Raska Laurel K. , Lynch James F. , Colosi John A. , Siegmann William L.
Published: September 2013

Recent shallow water experiments suggest that 3-D ocean variability can produce significant intensity variations with a broad spectrum of time scales. In particular, nonlinear internal waves (NIWs) can cause acoustical ducting when the NIW and acoustic propagation directions are nearly at right angles. The sound-speed curvature induced by NIWs play an important role in controlling acoustic focusing, as shown by recent numerical simulations. However, NIWs are not perfect plane waves and an acoustic signal propagating roughly perpendicular to an NIW will encounter a fluctuating duct. We present 3-D numerical simulations in which multiple NIW packets are used to emulate the along-duct variability and its effect on acoustic intensity changes. A rough hierarchy of NIW feature characteristics, based on their intensity influence, will be described. [Work supported by ONR.]
Analytic mean and variance of forward propagated field through random internal waves and subbottom anomalies with Rayleigh–Born scattering
Authors: Ratilal Purnima , Chen Tianrun , Makris Nicholas C.
Published: September 2013

The mean and variance of the field propagated through a waveguide containing random internal waves or subbottom anomalies is modeled using a modal solution [Ratilal and Makris, J. Acoust. Soc. Am. 114, 2428 (2003)] that analytically expresses the effects of dispersion, attenuation, and redistribution of modal energy due to multiple scattering in the forward direction. The scatter function of an elemental volume of inhomogeneity in density and compressibility is modeled using the Rayleigh–Born approximation. Simulations in both continental shelf and deep water waveguides quantitatively show how the relative magnitude of coherent versus incoherent intensity varies with range in typical internal wave fields and subbottom environments.
Frequency dependence of the sound fluctuations in the presence of internal solitary waves in SWARM’95
Authors: Badiey Mohsen , Katsnelson Boris , Pereselkov Serguey , Lynch James
Published: September 2013

In this paper the propagation of sound pulses in a shallow-water region in the presence of internal soliton train (IS) traveling approximately across an acoustic track of 15 km is studied. Broadband sound pulses were produced by an airgun (shots with frequency band about 30–120 Hz) and an electromechanical (J15) sound source (LFM sweeps with frequency band 50–200 Hz). Experimental data show significant correlation of sound fluctuations with IS motion. In addition, difference in the excitation source causes different modal energy partitioning in the waveguide. Modeling is carried out within the framework of the theory of vertical modes and horizontal rays (or PE in the horizontal plane). Calculations give a good agreement for temporal fluctuations of the sound energy for the sources used. It is shown that frequency dependence of intensity fluctuations is connected with the frequency dependence of refraction index of horizontal rays due to the 3D nature of these fluctuations. [Work supported by ONR and RFBR, Grant 03-05-64568.]
A modified approach to scintillation index analysis of intensity
Authors: Lutz Steven , Bradley David , Culver R. Lee
Published: September 2013

Intensity fluctuations of direct and refracted paths measured during a field test near San Clemente Island in August 2002 are presented. Signals used include 20 and 40 kHz CW pulses with 0.14- and 1.0-ms durations. Source to receiver separation was 1 km. Towed CTD data, also collected during the experiment, is presented. Acoustic signals will be analyzed using a matched filter. Temperature variations will be computed as mean-square fluctuations of the index of refraction. The intensity fluctuation records have lower scintillation indices than may be expected from the existing theory [e.g., Uscinsky et al., J. Acoust Soc. Am. 74 (1983)]. However, our frequencies are one to two orders of magnitude higher than those used in experiments for which this theory was developed and our propagation ranges are considerably shorter. More significantly, the acoustic data records are of considerably shorter duration (∼30 s) than previous experiments. To address the issue of the short record’s inability to detect larger structures in the water column, filtering is applied to the sound speed field before the calculation of the correlation length (patch size). [Work supported by ONR Code 321US.]
Low-frequency reverberation signal in shallow water in presence of internal waves
Authors: Katsnelson Boris , Pereselkov Sergey , Petnikov Valery
Published: September 2013

The reverberation of low-frequency (100–400 Hz) sound in shallow water is considered. It is supposed that reverberation signals are formed by summarizing from circle area (radius about 50 km) as result of sound field backscattering on bottom surface. The developed model of reverberation takes into account mode coupling caused by background internal waves in shallow water and depending on direction of backscattered signal. Influence of internal waves on space-time structure of reverberation signal is considered for two cases: single-modal and multi-modal. The computer simulation shows that internal waves lead to significant temporal fluctuations of reverberation signal in both cases. The results of computer simulation are compared with data of experimental research in the Barents Sea. [Work supported by RFBR, Grants 02-02-16509 and 03-05-64568.]
Not your grandfather’s concert hall
Authors: Cooper Russell , Malenka Richard , Griffith Charles , Friedlander Steven
Published: September 2013

The opening of Judy and Arthur Zankel Hall on 12 September 2003, restores Andrew Carnegie’s original 1891 concept of having three outstanding auditoriums of different sizes under one roof, and creates a 21st-century venue for music performance and education. With concerts ranging from early music to avant-garde multimedia productions, from jazz to world music, and from solo recitals to chamber music, Zankel Hall expands the breadth and depth of Carnegie Hall’s offerings. It allows for the integration of programming across three halls with minifestivals tailored both to the size and strengths of each hall and to the artists and music to be performed. The new flexible space also provides Carnegie Hall with an education center equipped with advanced communications technology. This paper discusses the unique program planned for this facility and how the architects, theatre consultants, and acousticians developed a design that fulfilled the client’s expectations and coordinated the construction of the facility under the floor of the main Isaac Stern Auditorium without having to cancel a single performance.
Baleen whale infrasonic sounds: Natural variability and function
Authors: Clark Christopher W.
Published: September 2013

Blue and fin whales (Balaenoptera musculus and B. physalus) produce very intense, long, patterned sequences of infrasonic sounds. The acoustic characteristics of these sounds suggest strong selection for signals optimized for very long-range propagation in the deep ocean as first hypothesized by Payne and Webb in 1971. This hypothesis has been partially validated by very long-range detections using hydrophone arrays in deep water. Humpback songs recorded in deep water contain units in the 20–l00 Hz range, and these relatively simple song components are detectable out to many hundreds of miles. The mid-winter peak in the occurrence of 20-Hz fin whale sounds led Watkins to hypothesize a reproductive function similar to humpback (Megaptera novaeangliae) song, and by default this function has been extended to blue whale songs. More recent evidence shows that blue and fin whales produce infrasonic calls in high latitudes during the feeding season, and that singing is associated with areas of high productivity where females congregate to feed. Acoustic sampling over broad spatial and temporal scales for baleen species is revealing higher geographic and seasonal variability in the low-frequency vocal behaviors than previously reported, suggesting that present explanations for baleen whale sounds are too simplistic.
Bubble translation and deformation induced by ultrasound radiation force
Authors: Ilinskii Yurii A. , Meegan G. Douglas , Zabolotskaya Evgenia A. , Emelianov Stanislav Y.
Published: September 2013

Measurement of small-bubble dynamics has been proposed for the remote evaluation of tissue elasticity [Erpelding et al., Proc. IEEE Ultrasonics Symp., 554–557, 2003]. For example, a microbubble can be produced within the cornea during femtosecond laser surgery and its response to a pulsed ultrasonic radiation force can be measured. The bubble’s translation, deformation, and oscillation can be directly related to the mechanical properties of surrounding tissue information that is required for optimization of the surgical procedure. In the work reported here, a model was developed to predict the translation and deformation of an initially spherical bubble in a soft viscoelastic medium as induced by radiation pressure. The extent of bubble translation and deformation is dictated by the elastic stress and viscous forces that oppose the radiation pressure. Numerical simulations predict static, periodic, and transient translation of the bubble in response to continuous, periodic, and pulsed waveforms, respectively. The model also predicts the deformation of the bubble. The results indicate increased deformations with increased bubble translations. Overall, the model can be used to determine the local shear modulus and viscosity of the medium based on measurements of gas-bubble displacement. [Work supported by ARL:UT IR&D.]
Plane-wave decomposition by spherical-convolution microphone array
Authors: Rafaely Boaz , Park Munhum
Published: September 2013

Reverberant sound fields are widely studied, as they have a significant influence on the acoustic performance of enclosures in a variety of applications. For example, the intelligibility of speech in lecture rooms, the quality of music in auditoria, the noise level in offices, and the production of 3D sound in living rooms are all affected by the enclosed sound field. These sound fields are typically studied through frequency response measurements or statistical measures such as reverberation time, which do not provide detailed spatial information. The aim of the work presented in this seminar is the detailed analysis of reverberant sound fields. A measurement and analysis system based on acoustic theory and signal processing, designed around a spherical microphone array, is presented. Detailed analysis is achieved by decomposition of the sound field into waves, using spherical Fourier transform and spherical convolution. The presentation will include theoretical review, simulation studies, and initial experimental results.
Spatial release from informational masking
Authors: Rakerd Brad , Aaronson Neil L.
Published: September 2013

A new method for investigating spatial release from informational masking was developed and employed in two experiments. The new method is computer controlled and efficient. It employs the versatile coordinate response measure speech stimulus set [Bolia et al., J. Acoust. Soc. Am. 107, 1065 (2000)]. The experiments were conducted in an anechoic room, with a primary loudspeaker in front of the listener and a secondary loudspeaker at 60 deg to the right. Target messages were presented from the primary speaker only. For a standard, distractor messages, simultaneous with the target, were also presented from the primary speaker only. Spatial release was measured by presenting the distractors from both primary and secondary speakers with a temporal offset. Experiment 1 fixed the offset (secondary leading, +4 ms) and varied the number of distractors (1 to 3) and the target-to-distractor ratio (−12 to +4 dB). Masking release, sometimes as large as 10 dB, was found for all combinations of these variables. Experiment 2 varied the offset over a wide range of values. Substantial release from masking was found for both positive and negative offsets, but only in the range in which speech echoes are suppressed (<50 ms). [Work supported by NIDCD grant DC 00181.]
Lateral suppression preserves speech intelligibility at high intensities
Authors: Bashford James A. , Warren Richard M. , Lenz Peter W.
Published: September 2013

The intelligibility of narrowband speech decreased 23% when its level was raised from 45 to 75 dB. However, when flanking bands of low-pass and high-pass white noise were added, intelligibility at the higher speech level recovered by as much as 65%. Recovery appears to be due to lateral suppression counteracting overloading effects of auditory-nerve (AN) firing-rate saturation at high speech intensities. Findings supporting this hypothesis include: (1) the absence of intelligibility enhancement at the lower speech level; (2) a greater effect of the higher frequency flanking noise band at a low noise level; and (3) equivalent effects of continuous versus gated flanking noise, inconsistent with firing-rate adaptation. In addition, there was no intelligibility increase when the flanking noise and narrow-band speech were delivered to opposite ears of listeners. These behavioral results are consistent with previous physiological observations and models of lateral suppressive interactions occurring in the lower auditory pathway. It appears that the noise-induced intelligibility recovery is produced via lateral inhibition of saturated AN-fiber input to neurons of the cochlear nucleus, with a possible additional contribution from mechanical (two-tone) suppression evoked within the cochlea and likely not involving olivocochlear feedback. [Work supported by NIH.]
Revealing criteria which underlie judgments of auditory unpleasantness
Authors: Zimmer Karin , Ellermeier Wolfgang , Schmid Christian
Published: September 2013

The usefulness of probabilistic choice models in attaining metric scales of sensation magnitude is demonstrated by scaling the perceived unpleasantness of environmental sounds. Seventy-four subjects made pairwise comparisons of the unpleasantness of 12 binaurally recorded sounds. The stimuli varied considerably in loudness, timbre, and temporal envelopes. A preference-tree choice model accounted well for the structure underlying the data, indicating that subjects changed criteria when evaluating different sound pairs, and that these criterion changes combined in a lawful way, making it possible to measure unpleasantness on a ratio scale across the entire set of sounds investigated. The sounds could be grouped according to their (nonacoustical) intrusiveness, and loudness. A subsequent multiple-regression analysis showed that in the subgroups identified, a combination of psychoacoustical sharpness and roughness explained the unpleasantness-scale values very well; rcorr2=0.96. It is thus illustrated that choice models provide an explicitly stated theory of the observers’ decision behavior, with built-in checks of the consistency of judgments, and statistical tests to validate if the attempt at (ratio) scale construction succeeded. This is in contrast to techniques of ‘‘direct’’ scaling, e.g., magnitude estimation, in which the scale level has to be assumed bona fide. [Work supported by Centercontract on Sound Quality, Aalborg University.]
Segmental differences in the visual contribution to speech intelligibility
Authors: Nielsen Kuniko
Published: September 2013

It is well known that the presence of visual cues increases the intelligibility of a speech signal (Sumby and Pollack, 1954). Although much is known about segmental differences in visual-only perception, little is known about the contribution of visual cues to auditory–visual perception for individual segments. The purpose of this study was to examine (1) whether segments differ in their visual contribution to speech intelligibility, and (2) whether the contribution of visual cues is always to increase speech intelligibility. One talker produced triples of real words containing 15 different English consonants. Forced-choice word-identification experiments were carried out with these recordings under auditory–visual (AV) and auditory-only (A) conditions with varying S/N ratios, and identification accuracy for the 15 consonants was compared for A versus AV conditions. As expected, there were significant differences in the visual contribution for the different consonants, with visual cues greatly improving speech intelligibility for most segments. Among them, labio-dentals and interdentals show the largest improvement. Although individual perceivers differed in their performance, the results also suggest that for some consonants, the presence of visual cues can reduce intelligibility. In particular, the intelligibility of [r] decreased significantly in the AV condition, being perceived as [w] in most cases.
The effects of age on identification of temporally altered visual-only speech signals
Authors: Spehar Brent , Tye-Murray Nancy , Sommers Mitchell S.
Published: September 2013

The purpose of the present study was to investigate the effects of age on the ability to identify temporally altered visual speech signals (i.e., visual-only presentations). Young (18–26) and older (over age 65) adults identified words placed in final position within a carrier phrase. Digital signal processing was used to compress (speed) and expand (slow) both the carrier phrase and the target words by 33%. Thus, the resultant stimuli were either 67% or 133% of the original duration. Speaking rate (expanded, unmodified, and compressed) was manipulated within subjects. Overall performance for both older and younger adults was significantly reduced for the speeded, compared with either the unaltered or the slowed condition. Furthermore, although older adults had significantly lower speechreading scores than younger adults, they did not exhibit disproportionate declines for the temporally altered conditions. These results stand in contrast to previous findings with auditory-only presentations in which older adults show significantly greater declines than younger adults as a consequence of increased speaking rate. Taken together, these findings argue against a generalized slowing of information processing in older adults and instead point to modality-specific changes in temporal processing abilities.
Fundamental frequency perturbation indicates perceived health and age in male and female speakers
Authors: Feinberg David R.
Published: September 2013

There is strong support for the idea that healthy vocal chords are able to produce fundamental frequencies (F0) with minimal perturbation. Measures of F0 perturbation have been shown to discriminate pathological versus healthy populations. In addition to measuring vocal chord health, F0 perturbation is a correlate of real and perceived age. Here, the role of jitter (periodic variation in F0) and shimmer (periodic variation in amplitude of F0) in perceived health and age in a young adult (males aged 18–33, females aged 18–26), nondysphonic population was investigated. Voices were assessed for health and age by peer aged, opposite-sex raters. Jitter and shimmer were measured with Praat software (www.praat.org) using various algorithms (jitter: DDP, local, local absolute, PPQ5, and RAP; shimmer: DDA, local, local absolute, APQ3, APQ5, APQ11) to reduce measurement error, and to ascertain the robustness of the findings. Male and female voices were analyzed separately. In both sexes, ratings of health and age were significantly correlated. Measures of jitter and shimmer correlated negatively with perceived health, and positively with perceived age. Further analysis revealed that these effects were independent in male voices. Implications of this finding are that attributions of vocal health and age may reflect actual underlying condition.
An improved correction formula for the estimation of voice source harmonic magnitudes
Authors: Iseli Markus , Alwan Abeer
Published: September 2013

Information about voice and talker characteristics, or voice quality, can be gained from glottal flow estimates. Many voice quality parameters, such as the open quotient (OQ), depend on an accurate estimate of the glottal flow (voice source) spectrum. It is known that OQ, for example, is correlated with the magnitude difference of the first two harmonics (H1–H2) of the voice source spectrum [Holmberg et al., ‘‘Comparisons among aerodynamic, electroglottographic, and acoustic spectral measures of female voice,’’ J. Speech Hear. Res. 38, 1212−1223 (1995)]. To obtain an accurate estimate of the voice source spectral harmonics, the influence of vocal−tract resonances needs to be removed. In Hanson, Ph.D. dissertation, Harvard University (1995), a correction formula which removes the effect of F1 on H1 and H2 was presented. In this work, an improved correction formula for the estimation of source harmonics′ magnitudes is presented. The new correction formula accounts for the bandwidths of vocal−tract resonances, and most importantly, is not limited to the analysis of nonhigh vowels. H1−H2 estimates, using the proposed technique with synthesized vowels /a/, /i/, and /u/ generated with the LF and the KLGLOTT88 models, are very accurate. [Work supported in part by the NSF.]
An acoustic and electroglottographic study of V-glottal stop-V in two indigenous American languages
Authors: Esposito Christina M. , Scarborough Rebecca
Published: September 2013

Both Pima, a Uto-Aztecan language spoken in Arizona, and Santa Ana del Valle Zapotec (SADVZ), an Otomanguean language spoken in Oaxaca, Mexico, have sequences of two vowels separated by an intervening glottal stop. In both languages, this V?V sequence becomes reduced in certain occurrences, with the perceptual effect of the loss of /?/ in Pima and the loss of V2 in SADVZ. The purpose of this study is to provide an acoustic and electroglottographic (EGG) description of these sequences in both their full and reduced forms, prompted by varying speech rate. Two acoustic measures of phonation type (H1–H2, H1–A3) and two EGG measures (OQ and peak closing velocity) were made at vowel midpoints and adjacent to /?/. For Pima, an issue of interest is what properties of the /V?V/ sequences (when V1=V2) allow them to be distinguished from phonemic long vowels in the reduced forms where /?/ is lost. It is hypothesized that /?/ will be preserved as vowel glottalization. For SADVZ, an important question is why the vowels sound creaky despite a lack of spectral evidence for creak. It is hoped that more direct EGG measures will show the perceived phonation.