bluuebunny/crossref_metadata_2025 huggingface dataset:
Bilinguals’ categorical perceptual shift when producing Spanish or English words: Electrophysiological correlates
Authors: Garcia-Sierra Adrian , Champlin Craig
Published: September 2013

In a previous study Mexican–American bilinguals identified synthetic /ga/-/ka/ syllables varying in VOT in two language conditions (Spanish and English). The perceived voicing boundary of the bilinguals varied depending on the language they had produced before the test session. In the present study event-related potentials (ERPs) were recorded from bilinguals in both language conditions. A classic oddball paradigm was used to obtain mismatch negativity (MMN) responses as an indication of categorical perception. Participants were tested in two sessions one week apart with the language conditions counterbalanced. In each test session, the electrophysiological recording was paused every 5 min in order to avoid MMN habituation. During the pause, bilinguals produced a set of Spanish or English words to keep them focused in the language of interest. The results indicated smaller MMN amplitude in the language condition where deviant and standard stimuli were more likely to be perceived as part of the same category. [Work supported by the Department of Communication Sciences and Disorders Univ. of Texas—Austin.]
Perception of a non-native speech contrast: Voiced and voiceless stops as perceived by Tamil speakers
Authors: Tur Sylwia
Published: September 2013

The effect of linguistic experience plays a significant role in how speech sounds are perceived. The findings of many studies imply that the perception of non-native contrasts depends on their status in the native language of the listener. Tamil is a language with a single voicing category. All stop consonants in Tamil are phonemically voiceless, though allophonic voicing has been observed in spoken Tamil. The present study examined how native Tamil speakers and English controls perceived voiced and voiceless bilabial, alveolar, and velar stops in English. Voice onset time (VOT) was manipulated for editing of naturally produced stimuli with increasingly longer continuum. Perceptual data was collected from 16 Tamil and 16 English speakers. Experiment 1 was an AX task in which subjects responded same or different to 162 pairs of stimuli. Experiment 2 was a forced choice ID task in which subjects identified 99 individually presented stimuli as pa, ta, ka or ba, da, ga. Experiments show statistically significant differences between Tamil and English speakers in their perception of English stop consonants. Results of the study imply that the allophonic status of voiced stops in Tamil does not aid the Tamil speakers in perceiving phonemically voiced stops in English.
Simultaneously multiple-depth coherent communications using time reversal
Authors: Song Heechun , Hodgkiss W. S. , Kuperman W. A. , Roux Philippe , Akal T. , Stevenson M.
Published: September 2013

A recent time reversal experiment demonstrated that multiple foci can be projected from an array of sources to the same range but at different depths. This ‘‘multiple input, multiple output (MIMO)’’ process potentially can improve the information data rate. This paper presents the experimental results of binary phase shift keying (BPSK) communications at 3.5 kHz with a 500-Hz bandwidth where two different messages were sent simultaneously to different depths at 9-km range in 110-m-deep shallow water.
Acoustical measurements in ancient Roman theatres
Authors: Farnetani Andrea , Fausti Patrizio , Pompoli Roberto , Prodi Nicola
Published: September 2013

The Greek and Roman theatres are among the most precious and spectacular items of cultural heritage in the Mediterranean countries. The theatres are famous not only for their impressive architecture, but also for the acoustic qualities. For this reason it is important to consider these theatres as an acoustical heritage and to study their sound field. Within the activities of the ERATO (identification Evaluation and Revival of the Acoustical heritage of ancient Theatres and Odea) project, acoustical measurements were taken in well-preserved ancient Roman theatres at Aspendos (Turkey) and Jerash (Jordan). Roman theatres have an impressive stage building that forms a back wall in the orchestra area, and it was found that, from the analysis of the acoustical parameters, the reverberation time (e.g., 1.7 s at middle frequencies in the theatre of Aspendos) is quite long compared not only with other open-space theatres but also with closed spaces. Contrary to modern halls the clarity is high and this fact, together with a low sound level in most of the seats, gives the sound field a unique character.
Hands-free human-machine interaction with voice
Authors: Juang B. H.
Published: September 2013

Voice is natural communication interface between a human and a machine. The machine, when placed in today’s communication networks, may be configured to provide automation to save substantial operating cost, as demonstrated in AT&T’s VRCP (Voice Recognition Call Processing), or to facilitate intelligent services, such as virtual personal assistants, to enhance individual productivity. These intelligent services often need to be accessible anytime, anywhere (e.g., in cars when the user is in a hands-busy-eyes-busy situation or during meetings where constantly talking to a microphone is either undersirable or impossible), and thus call for advanced signal processing and automatic speech recognition techniques which support what we call ‘‘hands-free’’ human-machine communication. These techniques entail a broad spectrum of technical ideas, ranging from use of directional microphones and acoustic echo cancellatiion to robust speech recognition. In this talk, we highlight a number of key techniques that were developed for hands-free human-machine communication in the mid-1990s after Bell Labs became a unit of Lucent Technologies. A video clip will be played to demonstrate the accomplishement.
Detecting sperm whale clicks in the presence of ambient and shipping noise using higher order moments
Authors: Larue James P. , Ioup George E. , Ioup Juliette W.
Published: September 2013

The single-receiver detection of various sources using higher order moments is demonstrated. The data for this study come from the Littoral Acoustic Demonstration Center experiment in the northern Gulf of Mexico in the summer of 2001. Results show that in a time-varying environment it may be more meaningful to use non-normalized statistics (e.g., using the fourth central moment rather than the kurtosis). A whale click is detected over a 35-ms window, i.e., with a sampling rate of 11718 samples per second, 40 samples are used to produce a statistic. In the past, energy and related detectors have been used for the single receiver detection of broadband signals produced by whale clicks. The presence of loud shipping noise, which is also broadband, tends to mask the clicks and make their detection difficult. Using short-time statistics may help mitigate this problem. Analysis with fractal exponents will be shown as well. [Research supported by ONR.]
Physiologic correlates to background noise acceptance
Authors: Tampas Joanna , Harkrider Ashley , Nabelek Anna
Published: September 2013

Acceptance of background noise can be evaluated by having listeners indicate the highest background noise level (BNL) they are willing to accept while following the words of a story presented at their most comfortable listening level (MCL). The difference between the selected MCL and BNL is termed the acceptable noise level (ANL). One of the consistent findings in previous studies of ANL is large intersubject variability in acceptance of background noise. This variability is not related to age, gender, hearing sensitivity, personality, type of background noise, or speech perception in noise performance. The purpose of the current experiment was to determine if individual differences in physiological activity measured from the peripheral and central auditory systems of young female adults with normal hearing can account for the variability observed in ANL. Correlations between ANL and various physiological responses, including spontaneous, click-evoked, and distortion-product otoacoustic emissions, auditory brainstem and middle latency evoked potentials, and electroencephalography will be presented. Results may increase understanding of the regions of the auditory system that contribute to individual noise acceptance.
Developmental and communicative factors affecting VOT production in English and Arabic bilingual and monolingual speakers
Authors: Khattab Ghada
Published: September 2013

VOT patterns were investigated in the production of three Lebanese–English bilinguals’ aged 5, 7, and 10, six aged-matched monolingual controls from the bilinguals’ immediate communities, and the parents of bilinguals and monolinguals. The aim was to examine the extent to which children exposed to two languages acquire separate VOT patterns for each language and to determine the factors that affect such acquisition. Results showed that VOT patterns for each bilingual child differed significantly across the two languages. But while the contrast in English resembled a monolingual-like model, that for Arabic exhibited persisting developmental features; explanations were offered in terms of the relationship between input and complexity of voicing lead production. Evidence was used from developmental changes that were noted for two of the bilingual subjects over a period of 18 months. English code-switches produced by the bilinguals during Arabic sessions exhibited different VOT patterns from those produced during English sessions, which underlined the importance of taking the language context into consideration. Finally, results from monolinguals and bilinguals showed that the short lag categories for the two languages were different despite a degree of overlap. Such findings require finer divisions of the three universal VOT categories to account for language-specific patterns.
Ecological echoes observed by moving biomimetic sonar characterize objects
Authors: Kuc Roman
Published: September 2013

This paper examines echoes from in situ foliage, similar to those observed by flying bats. A moving sonar converts echoes into spike sequences and applies neural-computational methods to estimate passing range and travel speed. Retro-reflectors and favorably oriented planar patches generate strong echoes (SEs), identified by spike firing rate. Linear sonar trajectories cause SEs to form hyperbolic patterns, termed glints, specified by passing range and travel speed. Passing-range specific detectors compare successive SE times with values in a table and tally coincidences. A glint terminates after a sufficient number of coincidences are tallied and two consecutive mismatches occur in the maximum-count detector. SE arrival jitter necessitates a coincidence window. Short windows identify individual glints while long windows generalize extended objects. SEs from distant objects exhibit almost constant incremental delays, used to estimate sonar travel speed, necessary for robust glint detection. Passing-range estimates may explain how bats can fly through small openings without collision.
Infrasonic pistonphone
Authors: Zuckerwar Allan J. , Teter John E. , Robbins William E.
Published: September 2013

A hand-held, battery-powered pistonphone was designed to calibrate infrasonic microphones in the field. With a battery voltage of 12 V, a prototype pistonphone provides a sound pressure level of 110±0.5 dB re 20 μPa at a frequency of 13.8 Hz. The microphone is inserted into an acoustic coupler, in which a stretched diaphragm is excited to generate infrasound. The diaphragm motion is generated by an eccentric ball bearing, such that the outer race does not rotate but remains in contact with the diaphragm at the same point during a complete rotation cycle. Thus this mechanism avoids sliding friction and insures a positive diaphragm displacement, independent of acoustic load. The diaphragm tension is adjusted to a sufficiently high level to prevent ‘‘floating’’ (separation from the eccentric) at the operating frequency. Further, the pistonphone is designed to have a high ‘‘thermal wave number’’ to insure adiabatic as opposed to isothermal wave propagation.
Method and system for calibrating acoustic receivers in borehole logging tools
Authors: Garcia Osuna Fernando , Ikegami Toru
Published: September 2013

Monopole and quadrupole contamination on dipole measurements is one of the main problems for sonic logging tools that employ arrays of acoustic receivers to measure a borehole’s dipole mode. The amplitude and phase mismatch of the array of sensors in acoustic logging tools plays an important role in the quality of dipole measurements. Acoustic receivers often have different sensitivities, and different sensitivities to the same wave field result in a greater possibility of no dipole contamination. Even similarly or identically manufactured receivers tend to report different amplitudes and time measurements (i.e., amplitude and phase mismatch). In practice, the no-dipole modes are removed by making the measurements at different azimuth and extracting the dipole mode from those that reject the other contaminating modes. Therefore, to improve rock formation slowness estimation and downhole modal computation, it is necessary to calibrate acoustic logging tools by detecting and correcting the amplitude and phase mismatch of the individual sensors mounted in the logging tools. A method and system for calibrating acoustic receiver arrays mounted in a downhole logging tool and the factors that affect their sensitivity are discussed in this paper.
The Sagrada Familia Cathedral where Gaudi envisaged his bell music
Authors: Yoshikawa Shigeru , Narita Takafumi
Published: September 2013

The Sagrada Familia Cathedral in Barcelona, Spain was constructed in 1882. According to Antoni Gaudi, who worked over its grand plan, the Cathedral was supposed to be a huge musical instrument as a whole in the event of completion. As as result, the music of bells was expected to echo through the air of Barcelona from the belfries. However, Gaudi’s true intention cannot be exactly known because the materials prepared by him were destroyed by war fire. If his idea of the Sagrada Familia as an architechtural music instrument is true, an acoustical balance should be considered between the roles of the Cathedral: bell music from the belfries and quiet service in the chapel. Basic structure of the Sagrada Familia seems to be an ensemble of twin towers. Following such speculation, we made a simplified acrylic 1/25-scale model of the lower structure of a twin tower located at the left side of the Birth Gate. The higher structure of this twin tower corresponds to the pinnacle where the bells should be arranged. The lower structure (about 43 m in actual height) has five passages connecting two towers. One of two towers includes five or six tandem columns whose ends are both squeezed to about 1.5 m in diameter. These columns seem to function as a kind of muffler. The location and shape of the roof over the nave is indefinite and tentatively supposed at the top of the lower structure. Based on our scale model, acoustical characteristics of the lower twin-tower structure as a muffler and acoustical differences between the exterior field and nave field will be reported and discussed.
Measurement of the frequency dependence of the ultrasonic parametric threshold amplitude
Authors: Teklu Alem A. , Declercq Nico F. , Breazeale Mack A.
Published: September 2013

The excitation of a liquid-filled cavity by ultrasonic waves was described as a parametric phenomenon [L. Adler and M. A. Breazeale, J. Acoust. Soc. Am. 48, 1077–1083 (1970)]. A standing ultrasonic wave is produced in the cavity by a drive transducer at one end and a rigid reflector at the other. Variations in the cavity length lead to frequencies lower than the drive frequency. Such a situation can be described by a modified Matthieu equation whose solution can be used to predict a threshold for parametric oscillation. Originally the threshold was assumed to decrease with frequency [L. Adler, Ph.D. dissertation, The University of Tennessee, 1969]. The apparatus used by Adler and Breazeale recently was refined for accurate measurement of the threshold amplitude for parametric excitation between 1 and 10 MHz. The measurement showed that in this range the threshold amplitude actually increases with increasing drive frequency. The results are compared with existing models.
Edge resonance in elastic bodies. The physical analysis of the phenomenon
Authors: Grinchenko Victor T. , Gorodetskaya Natalya S.
Published: September 2013

Edge resonance in elastic bodies of finite sizes is a specific phenomenon without analogs in wave fields in electrodynamics and acoustics. This phenomenon was examined by studying normal modes of finite elastic cylinders and plates. With excitation of the edge resonance, an unusual wave effect is formed. The eigenfrequency of an elastic body is independent of its geometrical size and, in some cases, even increases with increasing body dimension. Eigenfrequency of edge resonance is into the frequency range where only one propagating wave exists in the corresponding infinite cylinder or layer. It gives a basis for the general qualitative conclusion that edge resonance is a result of intensive excitation of evanescent waves. However, such an obvious idea does not open the nature of the edge mode formation. The analysis of longitudinal and shear components of propagating wave gives way to understanding specific features of reflection of normal wave in semi-infinite waveguides. The determining role of effects of transformation of longitudinal wave in shear wave and vice versa at reflection from free boundary is shown. Dependence of quantitative characteristics of these effects from Poisson’s ratio allows estimation of the quality factor of edge resonance and changes corresponding eigenfrequency.
Extracting magnitude estimations of loudness from pairwise judgments
Authors: Galanter Eugene
Published: September 2013

Four problems limit widespread applications of magnitude estimation scales. There is first a serious question about the meaning of the judgments. Second, the judgments appear to be intrinsically unreliable. Third, amalgamation methods used to strike averages from several observers are poorly understood. Finally, it is difficult to know how to evaluate a single entity as distinct from a stimulus domain by these methods. A new psychophysical method is described and demonstrated that can scale any perceptual or attitudinal continuum. Observers give a numerical estimate of the magnitude of a randomly selected stimulus relative to another such stimulus to which a computer has assigned a random number. The stimulus pairs vary at random from trial to trial. Ratios of these computer-person number pairs estimate the slope of the psychophysical function. The slope lets us normalize the judgments which can then be mapped onto the stimulus domain. Loudness functions for individuals are shown with none of the cusps or singularities of traditional magnitude estimations from individuals. [Work supported in part by NASA.]
How many rumbles are there? Acoustic variation and individual identity in the rumble vocalizations of African elephants (Loxodonta africana)
Authors: Soltis Joseph M. , Savage Anne , Leong Kirsten M.
Published: September 2013

The most commonly occurring elephant vocalization is the rumble, a frequency-modulated call with infrasonic components. Upwards of ten distinct rumble subtypes have been proposed, but little quantitative work on the acoustic properties of rumbles has been conducted. Rumble vocalizations (N=269) from six females housed at Disney’s Animal Kingdom were analyzed. Vocalizations were recorded from microphones in collars around subject necks, and rumbles were digitized and measured using SIGNAL software. Sixteen acoustic variables were measured for each call, extracting both source and filter features. Multidimensional scaling analysis indicates that there are no acoustically distinct rumble subtypes, but that there is quantitative variation across rumbles. Discriminant function analysis showed that the acoustic characteristics of rumbles differ across females. A classification success rate of 65% was achieved when assigning unselected rumbles to one of the six females (test set =64 calls) according to the functions derived from the originally selected calls (training set =205 calls). The rumble is best viewed as a single call type with graded variation, but information regarding individual identity is encoded in female rumbles.
Sources of uncertainty in Doppler sonar measurements of fish speed
Authors: Tollefsen Cristina D. S. , Zedel Len
Published: September 2013

A 250-kHz, 30-kHz bandwidth coherent Doppler sonar was evaluated to determine sources of uncertainty in fish speed measurements. Three separate tests were undertaken: (1) towtank tests using styrofoam balls to simulate fish, (2) tank tests with live free-swimming fish, and (3) field tests with wild free-swimming fish. The standard deviation in a single speed estimate was 9 cms−1 for styrofoam balls, 10–11 cms−1 for swimming fish observed from a dorsal aspect, and 19 cms−1 for swimming fish observed from a caudal aspect. The variation in precision was primarily due to the different signal-to-noise ratio (SNR) in each test: a larger SNR resulted in a smaller standard deviation. Doppler speed estimates were compared with independent estimates of target speed where possible. An accuracy of ±4 cms−1 was typical of Doppler speed estimates in all the experiments.
The design and analysis of new musical bells
Authors: McLachlan Neil M.
Published: September 2013

The design and analysis of a series of new musical bells will be presented in this paper. Modal analysis of a wide range of bell-like geometries using FEA revealed the presence and significance of transverse axial modes in unconstrained bell models, leading to a new understanding of the relationships between bell geometry and modal behavior. This understanding was used to adjust simple parametric models of bell geometry to arrive at appropriate geometries to begin numerical shape optimization for the design of bells with a range of desired overtone tunings. Pitch salience is well known to depend on the degree of harmonic relationships between pure tones in complex stimuli. Bells intended to produce a single, highly salient pitch were designed and manufactured with up to the first 7 overtones tuned to the harmonic series. Other bells with overtones tuned to subsets of two or three harmonic series were also designed and manufactured. These bells were intended to produce multiple pitch perceptions of approximately equal strength. Spectral analysis and range of numerical psycho-acoustic models are used to evaluate the sounds of manufactured bells against these design objectives. [I would like to acknowledge the close collaboration of Dr. Anton Hasell of Australian Bell.]
Simple reaction time to narrow-band and broadband noise
Authors: Wagner Eva , Florentine Mary , Buus So/ren , McCormack Joseph
Published: September 2013

The present study evaluates the relationship between loudness matches and simple reaction times (RT) in six normal-hearing subjects. Loudness matches between a narrow-band noise (125 Hz wide) and a broadband noise (1500 Hz) centered at 1000 Hz were made at levels from near threshold to near 100 dB SPL. For the same noises and level range, RT were also measured. In agreement with previous loudness-matching studies, as SPL increased the level difference between the noises needed to maintain equal loudness first increased, to around 10 dB at moderate SPLs, and then decreased. Except for one listener, the RT data show the same pattern. The level difference needed to maintain RT the same to the two noises first increased and then decreased. These results show that RT is closely related to loudness, but not to sensation level. If RT depended on sensation level, the level difference between the two noises needed to achieve equal RT would not change with SPL because the difference in sensation level between two sounds is constant as a function of SPL. Overall, the present data provide strong support for the contention that simple RT depends strongly on loudness. [Supported by NIH/NIDCD Grant No. R01 DC 02241.]
Relative intelligibility of dynamically extracted transient versus steady-state components of speech
Authors: Boston J. R. , Yoo Sungyub , Li C. C. , El-Jaroudi Amro , Durrant J. D. , Kovacyk Kristie , Karn Stacey
Published: September 2013

Consonants are recognized to dominate higher frequencies of the speech spectrum and to carry more information than vowels, but both demonstrate quasi-steady state and transient components, such as vowel to consonant transitions. Fixed filters somewhat separate these effects, but probably not optimally, given diverse words, speakers, and situations. To enhance the transient characteristics of speech, this study used time-varying adaptive filters [Rao and Kumaresan, IEEE Trans. Speech Audio Process. 8, 240–254 (2000)], following high-pass filtering at 700 Hz (well-known to have minimal effect on intelligibility), to extract predominantly steady-state components of speech material (CVC words, NU-6). The transient component was the difference between the sum of the filter outputs and the original signal. Psychometric functions were determined in five subjects with and without background noise and fitted by ogives. The transient components averaged filtered speech energy, but PBmax was not significantly different (nonparametric ANOVA) from that of either the original or highpass filtered speech. The steady-state components yielded significantly lower PBmax (p 3D 0.003) despite their much greater energy, as expected. These results suggest a potential approach to dynamic enhancement of speech intelligibility. [Work supported by ONR.]
Contribution of consonant versus vowel information to sentence intelligibility by normal and hearing-impaired listeners
Authors: Burkle T. Zachary , Kewley-Port Diane , Humes Larry , Lee Jae Hee
Published: September 2013

The purpose of this study was to examine the contribution of information provided by vowels versus consonants to sentence intelligibility in young normal-hearing (YNH) and elderly hearing-impaired (EHI) listeners. Sentences were presented in three conditions, with either the vowels or the consonants replaced with speech shaped noise, or unaltered. Sentences from male and female talkers in the TIMIT database were selected. EHI subjects listened at 95 dB SPL, and YNH subjects at both 95 and 70 dB SPL. Subjects listened to each sentence twice and were asked to repeat the entire sentence after each presentation. Words were scored correct if identified exactly. Average performance for unaltered sentences was greater than 94%. Vowel-present conditions were always significantly more intelligible than consonant-present conditions, similar to data reported by Cole and colleagues [Proceedings of ICASSP, 1996]. Across groups, performance in the vowel-present conditions exceeded that in the consonant-present conditions by 14% to 40%, although EHI subjects performed more poorly than YNH subjects. In contrast to written English, vowels in spoken language carry more information about sentences than consonants for both normal and hearing-impaired listeners. [Work supported by NIDCD-02229.]
Revised audibility-noise variance of speech recognition sensitivity model
Authors: Müsch Hannes , Buus So/ren
Published: September 2013

The speech recognition sensitivity (SRS) model [H. Müsch and S. Buus, J. Acoust. Soc. Am. 109, 2896–2909 (2001)] was used to predict normal-hearing listeners’ consonant-recognition performance in a nonsense-syllable context as measured in nine independent studies. By attempting to fit these data, the relation between the variance of the SRS model’s audibility noise σ2N and the speech-excitation to noise-excitation ratio SNRE in the auditory periphery was optimized. The best predictions were obtained when the audibility-noise variance was directly proportional to the noise-excitation power. Based on this finding it is suggested that the relation between audibility-noise variance and SNRE that was proposed in the original SRS paper be replaced by 10log10(σNi2)=−SNREi+B+10log10((zj− zi)/(19Barks)), where σNi2 is the audibility-noise variance in the band reaching from critical-band rate zi to zj, SNREi is the speech-excitation to noise-excitation ratio in that band expressed in dB, and B is a fitting constant that will be in the order of 13 dB. The model provided good predictions of the data with model parameters that are consistent with those of earlier studies. [Work supported by NIH/NIDCD Grant R01DC00187.]
Coherence and the Speech Intelligibility Index
Authors: Kates James , Arehart Kathryn
Published: September 2013

Noise and distortion reduce the sound quality in hearing aids, but there is no established procedure for calculating sound quality in these devices. This presentation introduces a new intelligibility and sound-quality calculation procedure based on the Speech Intelligibility Index [ANSI S3.5-1997]. The SII involves measuring the signal-to-noise ratio (SNR) in separate frequency bands, modifying the estimated noise levels to include auditory masking, and computing a weighted sum across frequency of the modified SNR values. In the new procedure, the estimated signal and noise levels are replaced with estimates based on the coherence between the input and output signals of the system under test. Coherence is unaffected by linear transformations of the input signal, but is reduced by nonlinear effects such as additive noise and distortion; the SII calculation is therefore modified to include nonlinear distortion as well as additive noise. For additive noise, the coherence calculation gives SII scores identical to those computed using the standard procedure. Experiments with normal-hearing listeners using additive noise, peak-clipping distortion, and center-clipping distortion are then used to relate the computed coherence SII scores with the subjects’ intelligibility and quality ratings. [Work supported by GN ReSound (JMK) and the Whitaker Foundation (KHA).]
ERP indices of speech processing in bilinguals
Authors: Garrido Karen , Hisagi Miwako , Shafer Valerie
Published: September 2013

The specific aim of this project was to examine perceptual differentiation of the vowel contrast [I-E] by early versus late bilingual Spanish–English speakers, compared to monolingual English speakers. Neither of these phonetic segments occur as phonemes in Spanish while they constitute phonemic contrast in English. For Spanish listeners, these vowels may be heard as variants of the Spanish phonemes [i] and [e], respectively. The formation of perceptual categories may be affected by exposure to two languages in which the phonemic status of phonetic segments differs. In the current study, electrophysiological measures (mismatched negativity—MMN) and behavioral measures (AX discrimination and identification) were employed to examine perception of a nine-step continuum resynthesized from natural tokens. Preliminary results indicate that early bilinguals show somewhat more categorical perception than monolinguals (i.e., sharper identification boundaries) of the nine-step continuum. MMN results, obtained during a task in which subjects were not attending to the auditory input, show clear MMNs for monolinguals for both cross- and within-category pairs. To date, results for early bilinguals show less clear indication of preattentive discrimination. The role of language experience and the relationship between the behavioral performance and the electrophysiological measures will be discussed.
Structural equation modeling applied to the prediction of word identification accuracy
Authors: Takayanagi Sumiko , Bernstein Lynne E. , Auer Edward T.
Published: September 2013

Five structural equation models (SEMs) were developed to examine explicitly the relative contribution of experiential (subjective frequency and word age of acquisition) and word similarity (lexical equivalence class size and phoneme equivalence class size) factors on word identification accuracy (WIA). WIA (percent word correct scores and word cost scores) was measured for 184 monosyllabic words under five presentation conditions: (1) visual-only speech; (2) high intelligibility vocoded auditory-only speech; (3) low intelligibility vocoded auditory-only speech; (4) high intelligibility vocoded audiovisual speech; and (5) low intelligibility vocoded audiovisual speech. The results showed that each factor can be treated as an isolated factor and can be measured explicitly. Furthermore, the relative strengths of their contributions varied as a function of intelligibility and the estimation power of the predictor variables. In addition, two models were developed to estimate audiovisual (conditions 4 and 5) WIA from experiential, visual- and auditory-similarity factors. Only the SEM of condition 4 fit the data, and the experiential and auditory factors contributed equally, but the visual factor did not contribute much to the WIA in this model. Advantages and limitations of SEM will be discussed.
The influence of task on gaze during audiovisual speech perception
Authors: Buchan Julie , Paré Martin , Yurick Micheal , Munhall Kevin
Published: September 2013

In natural conversation, visual and auditory information about speech not only provide linguistic information but also provide information about the identity and the emotional state of the speaker. Thus, listeners must process a wide range of information in parallel to understand the full meaning in a message. In this series of studies, we examined how different types of visual information conveyed by a speaker’s face are processed by measuring the gaze patterns exhibited by subjects watching audiovisual recordings of spoken sentences. In three experiments, subjects were asked to judge the emotion and the identity of the speaker, and to report the words that they heard under different auditory conditions. As in previous studies, eye and mouth regions dominated the distribution of the gaze fixations. It was hypothesized that the eyes would attract more fixations for more social judgment tasks, rather than tasks which rely more on verbal comprehension. Our results support this hypothesis. In addition, the location of gaze on the face did not influence the accuracy of the perception of speech in noise.
Cues to gender in children’s speech
Authors: Curtin Suzanne , Kiesling Scott
Published: September 2013

Awareness of one’s own gender emerges around 3 years and awareness that gender stays stable throughout life is evident by 4 years (Bee, 1998). This suggests that by 4 years of age, noticeable gender differences may emerge along a number of dimensions. The hypothesis tested here is that adults are able to identify the gender of 4-year-olds by voice quality alone. Sixteen four-year-olds were recorded saying the alphabet. Small portions of each recording were excised, and played to 40 adults. Adults were asked to identify the gender of the speaker. Subjects were able to correctly identify the gender of the child more often than chance. However, in the cases where a child’s gender was incorrectly identified, pitch did not play a significant role. Rather, it appears that formant structure is the best predictor (although not perfect), of how a child’s gender will be judged by voice (Perry, 2001). These results have important implications for our understanding of the linguistic cues that listeners use to identify the gender of speakers; they must be relying on phonetic cues that are much more subtle than gross pitch, lexical, phonological, or syntactic differences which are the usual provisions of language and gender research.
On the just-noticeable difference for tempo in speech
Authors: Quené Hugo
Published: September 2013

The rate or tempo of speech modulates listeners’ phonetic expectations, e.g., about VOT or about segment durations. In addition, variations in tempo contribute directly to speech communication, e.g., by expressing the communicative importance of speech fragments. It is not clear, however, how large tempo differences in speech have to be in order to be noticeable and to contribute to speech perception. This paper attempts to determine the jnd for tempo in speech, by means of detection of gradual changes in tempo. Participants listened to 10-s spoken texts, in which overall tempo was linearly accelerated (to 80%) or decelerated (to 120%) over a 5-s interval. They were instructed to press a button as soon as they detected a tempo change in the text; jnd’s were computed from their response times. Preliminary results suggest that the average jnd’s for tempo in speech are about 14% (acceleration) and 15% (deceleration). These values are far larger than those reported for tempo in music (about 3% to 6%), which suggests that only large changes in tempo are relevant for speech communication.
Acoustic–phonetic convergence among interacting talkers
Authors: Pardo Jennifer S.
Published: September 2013

Among other sources, acoustic–phonetic variability derives from both personal attributes of a talker and the social structure of a conversational setting. This research begins to detail the effects of such sources by examining the influence of conversational interaction on speech production. A set of talkers provided samples of speech before, during, and after participating in a paired conversational task. Using an A×B paradigm with a separate set of listeners, initial research found that paired talkers became more similar in phonetic repertoire, that this convergence persisted over a short delay, and that the degree of convergence was influenced by both the sex and task role of a talker. This paper presents detailed acoustic and talker scaling analyses from this conversational corpus in an attempt to chart the effects of personal and situational factors on speech variability. [Research supported in part by NIMH Grant No. 5F32MH64995.]
Acoustic and aerodynamic characteristics of ejectives in Amharic
Authors: Demolin Didier
Published: September 2013

This paper invetsigates the main phonetic characteristics that distinguishes ejectives from pulmonic sounds in Amharic. In this language, there are five ejectives that can be phonemically singleton or geminate. Duration measurements have been made in intervocalic position for pulmonic stops and for each type of ejective, taking into account the overall duration and VOT. Results show that ejective stops have a higher amplitude burst than pulmonic stops. The duration of the noise is shorter for ejective fricatives compared to pulmonic fricatives. At the end of ejective fricatives, there is a 30-ms glottal lag that is not present in pulmonic fricatives. Geminate ejectives are realized by delaying the elevation of the larynx. This can be observed on the spectrographic data by an increase of the noise at the end of the geminate ejectives. Aerodynamic data have been collected in synchronization with the acoustic recordings. The main observations are that pharyngeal pressures values are much higher than what is usually assumed (up to 40 CmH2O for velars) and that the delayed command in the elevation of the larynx of geminate ejectives is shown by two phases in the rise of pharyngeal pressure.
Acoustic correlates of Japanese expressions associated with voice quality of male adults
Authors: Kido Hiroshi , Kasuya Hideki
Published: September 2013

Japanese expressions associated with the voice quality of male adults were extracted by a series of questionnaire surveys and statistical multivariate analysis. One hundred and thirty-seven Japanese expressions were collected through the first questionnaire and careful investigations of well-established Japanese dictionaries and articles. From the second questionnaire about familiarity with each of the expressions and synonymity that were addressed to 249 subjects, 25 expressions were extracted. The third questionnaire was about an evaluation of their own voice quality. By applying a statistical clustering method and a correlation analysis to the results of the questionnaires, eight bipolar expressions and one unipolar expression were obtained. They constituted high-pitched/low-pitched, masculine/feminine, hoarse/clear, calm/excited, powerful/weak, youthful/elderly, thick/thin, tense/lax, and nasal, respectively. Acoustic correlates of each of the eight bipolar expressions were extracted by means of perceptual evaluation experiments that were made with sentence utterances of 36 males and by a statistical decision tree method. They included an average of the fundamental frequency (F0) of the utterance, speaking rate, spectral tilt, formant frequency parameter, standard deviation of F0 values, and glottal noise, when SPL of each of the stimuli was maintained identical in the perceptual experiments.
AUVs as integrated, adaptive acoustic sensors for ocean exploration
Authors: Schmidt Henrik , Edwards Joseph R. , Liu Te-Chih , Montanari Monica
Published: September 2013

Autonomous underwater vehicles (AUV) are rapidly being transitioned into operational systems for national defense, offshore exploration, and ocean science. AUVs provide excellent sensor platform control, allowing for, e.g., accurate acoustic mapping of seabeds not easily reached by conventional platforms, such as the deep ocean. However, the full potential of the robotic platforms is far from exhausted by such applications. Thus, for example, most seabed-mapping applications use imaging sonar technology, the data volume of which cannot be transmitted back to the operators in real time due to the severe bandwidth limitation of the acoustic communication. The sampling patterns are therefore in general being preprogramed and the data are being stored for postmission analysis. This procedure is therefore associated with indiscriminate distribution of the sampling throughout the area of interest, irrespective of whether features of interest are present or not. However, today’s computing technology allows for a significant amount of signal processing and analysis to be performed on the platforms, where the results may then be used for real-time adaptive sampling to optimally concentrate the sampling in area of interest, and compress the results to a few parameters which may be transmitted back to the operators. Such adaptive sensing concepts combining environmental acoustics, signal processing, and robotics are currently being developed for concurrent detection, localization, and classification of buried objects, with application to littoral mine countermeasures, deep ocean seabed characterization, and marine archeology. [Work supported by ONR and NATO Undersea Research Center.]
Explaining extended linear features observed in remote sonar images of the New Jersey continental shelf break during Acoustic Clutter Experiments in 2001 and 2003
Authors: Lee Sunwoong , Ratilal Purnima , Makris Nicholas C.
Published: September 2013

Prominent acoustic clutter forming a lineated feature spanning more than 10 km has been repeatedly observed in long-range sonar imagery acquired during the Acoustic Clutter Experiments in 2001 and 2003. The lineated feature appears on the continental shelf near the shelf break for downslope sonar positions. It is hypothesized that this lineated feature is caused by scattering from fish shoals, seafloor slopes, or subbottom geology such as the R-reflector. A range-dependent reverberation and scattering model using the parabolic equation [Ratilal et al., J. Acoust. Soc. Am. 114, 2302 (2003)] is employed to test these various hypotheses by model–data comparison using high resolution bathymetry, subbottom profiles, and fish density data acquired in support of the long-range acoustic measurements.
Classification of stop consonant place of articulation
Authors: Suchato Atiwong
Published: September 2013

In this study we develop an experimental procedure for examining the relative importance of knowledge-based cues for identifying place of articulation for stop consonants. A set of acoustic attributes is selected for place classification of stops: amplitude and energy of burst, formant movement of adjacent vowels, spectrum of noise after the release, and some temporal cues. The ability of each attribute to separate the three places is evaluated by the classification error based on the distributions of its values for the three places, and another quantifier based on F ratio. These two quantifiers generally agree and show how well each individual attribute separates the three places. Linear discriminant function analysis is used to address the relative importance of these attributes when combinations are used. Their discriminating abilities and the ranking of their relative importance to the classification in different vowel and voicing contexts are reported. The overall findings are that attributes relating to the burst spectrum in relation to the vowel contribute most effectively, while formant transition is somewhat less effective. The approach used in this study can be applied to different classes of sound, as well as stops in different noise environments. [Work supported by NIH Grant Number DC 02978.]
Obtaining a palatal trace for ultrasound images
Authors: Epstein Melissa A. , Stone Maureen , Pouplier Marianne , Parthasarathy Vijay
Published: September 2013

This paper presents methods for collection and display of the palate with ultrasound, for use as a reference for tongue movements. Ultrasound does not usually capture structures other than the tongue, because the air above the tongue in the vocal tract reflects the ultrasound beam back to the transducer. However, when the tongue touches the palate, the ultrasound beam is transmitted through the soft tissue until it reaches and is reflected by the palatine bone. The tongue touches the palate during swallowing and some speech sounds. The palate contour can be traced from these images. The paper presents a corpus of speech and swallowing tasks that can be used to create a full palatal trace. The corpus is tested on a subject for whom it is easy to collect palatal images and a subject for whom it is difficult to collect palatal images. The availability of a palate will enhance our ability for data quantification from ultrasound images. In combination with tongue contours, the palate contour allows the computation of linguistically important measures, such as the constriction degree, area functions, and L2 norms. [Work supported by NIH RO1-DC01758 and T32-DE07309.]
A new taxonomy of American English /r/ using MRI and ultrasound
Authors: Tiede Mark K. , Boyce Suzanne E. , Holland Christy K. , Choe K. Ann
Published: September 2013

In this work we present preliminary results from a large scale production study of American English liquids. MRI and ultrasound have been used to image 20 subjects producing /r/ and /l/. Subjects were native speakers, representative of the main American dialects, and balanced between sexes. MRI data were collected volumetrically for recovery of three-dimensional tongue shape. In addition, a short (1 s) midsagittal protocol was used in conjunction with ultrasound scanning to confirm the validity of the sustained production required for volumetric imaging. Our results show tongue shapes not inconsistent with the six main types found by Delattre and Freeman (1968), but their range and variety suggest that either additional canonical shapes or a different organizational principal (such as palatal shape) is motivated. We have also observed consistent patterns of tongue grooving associated with different midsagittal shapes, from the parasagittal data not accessible from the Delattre and Freeman cineradiography. In addition to this 3D-based taxonomy of /r/ tongue shapes we present similar data for lateral productions, and the associated acoustic structures for both. [Research supported by NIH.]