bluuebunny/crossref_metadata_2025 huggingface dataset:
The sonar beam of big brown bats (Eptesicus fuscus) during landing
Authors: Koblitz Jens C. , Stilz Peter , Pflästerer Wiebke , Melcon Mariana , Schnitzler Hans-Ulrich
Published: October 2013

The parameters signal duration, pulse interval, and frequency have previously been used to describe the approach behavior of landing bats. An array with 16 microphones was used to investigate additional parameters during the approach flight of landing big brown bats (Eptesicus fuscus). For each signal emitted the position of the landing bat in relation to the microphone array was determined using a 3-D video system, and the width, maximum intensity, and aiming direction of the sonar beam were calculated. The approach to the landing site begins at a distance of about 1.4 m when the bats pick up the landing site with their sonar beam. This focusing on the landing site is indicated by a clear decrease of the deviation between beam aiming and direction to the landing position. The maximum intensity of the sonar beam is reduced by about 6 dB per half distance during the last 2 m of the approach, which indicates a gain control mechanism. The width of the sonar beam remains constant throughout the whole approach.
‘‘Vocal grooming’’ in an eusocial subterranean rodent: The naked mole-rat (Heterocephalus glaber)
Authors: Yosida Shigeto , Okanoya Kazuo , Suzuki Chizuko , Nanvuh Sanae , Okanoya Kazuo
Published: October 2013

The naked mole-rat is a unique communal-living rodent of east Africa. In a subterranean environment, this small rodent species has a complex hierarchical society with labor division that is comparable to those of bees and ants. They are also known for their extensive vocal repertory of more than 17 sounds, which might have evolved as an alternative to visual cues, and which contributes to maintaining its society. We showed that their most frequent vocalization, the soft-chirp (SC), has an antiphonal nature, and it might function for rank-identification and reconciliation purposes. The SC is elicited either by another’s SC or physical touch. We analyzed acoustic properties of SC elicited by touching the animals, and found that it varies according to the body mass. The emission rate was highest among larger (superior) animals, but the smaller (inferior) of the two emitted SCs more frequently when observing behavior of two interacting animals. Playback experiments revealed that the use of SC generally follows these two rules: smaller animals vocalize more often than larger ones, and larger ones respond only to smaller animals’ SCs. These features of SC resemble grooming behavior among primates.
Neural responses to communication sound in the inferior colliculus of the naked mole-rat
Authors: Tokin Shizuka , Tanaka Kohichi , Tokin Shizuka , Okanoya Kazuo
Published: October 2013

The naked mole-rat (Heterocephalus glaber) is a highly social subterranean rodent that lives in Eastern Africa. Because they a dig burrow system and spend most of their lives underground, they are functionally blind and rely heavily on auditory information. They have at least 17 different vocalizations, which are associated with specific behavioral contexts. In this study, we focused on the soft chirp (SC), which is one of the most frequent vocalizations in this species, and recorded neural responses to synthesized SCs in the inferior colliculus. We found that the responses could be divided into three groups based on their response patterns. These response patterns represented the duration or frequency of stimuli. In addition, we also found that the number of spikes changed with the degree of frequency modulation. From these results, we hypothesized that the vocalizations of naked mole-rats can be represented by integrating the activity of such neurons that respond to a specific feature of sound.
Imaging propagation speed of pulsive vibration in the heart wall for healthy subjects and patients with old myocardial infarction
Authors: Kanai Hiroshi , Watanabe Sachiko , Saijo Yoshifumi , Tanaka Motonao
Published: October 2013

This study presents a novel method that noninvasively visualizes myocardial heterogeneity for healthy subjects and patients with old myocardial infarction. By a sparse sector scan, the myocardial minute motions were measured simultaneously at about 1000 points in the heart wall at a high frame rate. We have found that a pulsive vibration is excited by aortic-valve closure [H. Kanai and Y. Koiwa, Ultrasound Med. Biol. 27, 481–498 (2001)]. The consecutive spatial distributions of the vibrations reveal that the vibration propagates from the root of the aortic valve to the apex [H. Kanai, IEEE Trans. UFFC. 51, 1931–1942 (2005)]. In this study, the method was applied to seven healthy subjects and five patients, and the spatial distribution of the propagation speed of the vibration is also visualized. For all healthy subjects, the propagation of the pulsive vibration was visible both in longitudinal-axis and apical views, and there is spatial difference in the propagation speed; 4.3±0.5 m/s for the high echo area and 2.9±0.4 m/s for the low echo area, for a 60-Hz component. For patients, the propagation speed in the diseased area is about 30% lower than the normal area. These preliminary results indicate that the method has a potential for revealing myocardial heterogeneity.
Professor Floyd Dunn’s contribution to understanding the biological effects of ultrasound
Authors: Stratmeyer Mel E.
Published: October 2013

During Professor Dunn’s career, ultrasound exposure has evolved from being used to induce dramatic tissue effects in animals to routine diagnostic fetal imaging in humans. An understanding of the fundamental mechanisms and dosimetric parameters involved in ultrasound-induced biological effects was essential to allow ultrasound to be clinically used for tissue destruction, physical therapy, and routine diagnostic imaging. Professor Dunn’s early research and the research of other prominent scientists, many of them trained by Professor Dunn, will be discussed to demonstrate advancements in our understanding of the biological effects of ultrasound.
Development of novel biologically inspired directional microphones
Authors: Miles Ronald N. , Cui Weili , Su Quang , Wu Rui , Tan Lin , Liu Yang , Jones Stephen A. , Mohnankrishnaswami Venkatesh , Strait Thomas , Butler William , DiBernardo David , Degertekin F. Levent , Bicen Baris , Lee Wook , Jeelani Kamran
Published: October 2013

The development of novel directional microphones for hearing aids is described. The mechanisms underlying the design of these unusual microphones were inspired by our earlier study of the ears of the parasitoid fly Ormia ochracea [Miles, et al., J. Acoust. Soc. Am. 98, 3059–3070 (1995)]. The structure of Ormia’s ears inspired new approaches to the design of directional microphones that have the potential to be more sensitive and have lower thermal noise than typical miniature microphones. The mechanisms for directional hearing in this animal are discussed along with the engineering design concepts that they have inspired. Microphones have been fabricated out of silicon that employ either capacitive sensing or optical sensing to convert the diaphragm motion into an electronic signal. Measured results indicate that the directivity of these microphones is very similar to that of an ideal first-order differential microphone. In addition, novel microphone diaphragms have been fabricated that posses a second-order directional response. These can be used to achieve a significant reduction of unwanted background acoustic noise in hearing aid applications. [Work supported by NIH Grant 5R01DC005762-03, Sensing and Processing for Directional Hearing Aids, to RNM.]
Transverse variations of sound pressure in an ear canal occluded by a hearing aid
Authors: Stinson Michael R. , Daigle Gilles A.
Published: October 2013

The sound field in a model ear canal has been investigated experimentally and theoretically. The canal was cylindrical, 7.5-mm diameter, and terminated with a Zwislocki coupler to represent absorption by the human middle ear. The outer end of the canal was driven by a test hearing aid, with the acoustic output from a receiver entering the canal through a 1-mm port. The hearing aid was provided with a 20-mm-long vent, either 1 or 2 mm in diameter. The sound field inside the canal was measured using a specially designed 0.2-mm-diam probe microphone [Daigle and Stinson, J. Acoust. Soc. Am. 116, 2618 (2004)]. In parallel, calculations of the interior sound field were performed using a boundary element technique. Both calculations and experiment reveal large transverse variations of sound pressure level, as much as 25 dB at 8 kHz, near the inner face of the hearing aid. Variations are greatest near the outlet port of the receiver and the vent hole. Deeper into the canal, the transverse variations are less significant and, at depths greater than 5 mm, only a longitudinal variation remains. [Work supported by Gennum Corp.]
Methods of measuring the insertion loss of active noise reduction devices
Authors: Gauger Dan , Berger Elliott , Kieper Ronald , Casali John , Perala Chuck
Published: October 2013

As active noise reduction (ANR) becomes more common, the need has developed for the measurement of device attenuation, passive and active combined, for use in noise protection calculations. An experiment was conducted involving both REAT and MIRE measurements on five circumaural and two supra-aural ANR devices in two different laboratories. Subject selection and instruction were consistent with the ANSI S12.6-1997 Method B fitting paradigm for all measurements. MIRE was measured both using microphones mounted on canal-occluding plugs near the entrance of the canal (‘‘shallow MIRE’’) and using concha-mounted microphones with probe tubes extending near to the tympanic membrane and an unoccluded canal (‘‘deep MIRE’’); the latter measurements were done with the same device fitting trials as the REAT measurements. The two MIRE measurements were quite similar, with the shallow MIRE values typically better by margins of only 0.5 to 1.0 dB at all frequencies. A positive REAT minus MIRE difference at the lower frequencies consistent with the effects of physiological noise masking was observed. Various analyses of the data are presented and a recommendation is made for how ANR device total attenuation might be measured in a future standard as part of a hearing protector rating regime encompassing both passive and active devices.
Dosimeter measures of sound exposure experienced by university students
Authors: Yost William A. , Koita Noorah , Maslo Robert , Patel Prasad , Patel Ruchita , Ringhouse Brendan
Published: October 2013

There is increased concern about excessive sound exposure, especially in students, resulting from the use of Ipods and similar devices. Such exposure needs to be considered in light of the daily noise dose such users experience. In this study five university students wore noise dosimeters for 10 h per day for 5 days, and noise levels were recorded every minute. The students also maintained a diary of their activities (activities were noted at least every half hour) during the time they wore the noise dosimeters. The diary was standardized so that each student used the same diary format. Results indicating the noise levels, noise dose, and the relationship of the levels to the students activities will be presented and discussed. In general the noise exposure experienced by these students was usually mild (less than 60 dBA) to moderate (between 60 and 75 dBA).
Attempts to observe bubble fusion in deuterated acetone
Authors: Camara Carlos G. , Putterman Seth J. , Naranjo Brian , Hopkins Stephen D. , Suslick Kenneth S.
Published: October 2013

A pulsed neutron generator (PNG) and a radioactive source have been used to seed cavitation at dynamic pressures ranging up to 35 atm. No fusion signal above background has been observed. Our upper bound is less than 1E−4 of the signal claimed by R. P. Taleyarkhan et al. [Phys. Rev. Lett. 96, (2006)]. Reasons for the failure of bubble fusion in acetone and future directions will be discussed. [Research funded by DARPA. We thank Brian Kappus for valuable discussions.]
Influence of ultrasonic frequency on sonochemical reactions
Authors: Yasui Kyuichi , Tuziuti Toru , Kozuka Teruyuki , Towata Atsuya , Iida Yasuo
Published: October 2013

Numerical simulations of the pulsation of an air bubble have been performed for various ultrasonic frequencies (20 kHz to 1 MHz) and pressure amplitude taking into account the effect of nonequilibrium chemical reactions inside a bubble and that of nonequilibrium evaporation and condensation of water vapor at the bubble wall. The calculated results have revealed that as ultrasonic frequency decreases, the mole fraction of water vapor inside a bubble increases at the end of the bubble collapse. While the main oxidant created inside a vaporous bubble, which is defined as a bubble consisting mostly of water vapor at the end of the bubble collapse, is OH radical, that inside a gaseous bubble, which is defined as a bubble consisting mostly of noncondensable gas (air) at the end of the bubble collapse, is H2O2 or O atom when the bubble temperature is less than or more than 7000 K, respectively. Although the optimum acoustic amplitude for the oxidant’s creation inside a bubble increases as the ultrasonic frequency increases, the range of the suitable acoustic amplitude for the oxidants creation becomes wider. It possibly results in the optimum ultrasonic frequency for the oxidant’s creation reported in the literatures (200–600 kHz).
Comparison of sonoluminescence and water vapor plasma spectra
Authors: Sato Masanori , Okada Nagaya , Sugai Hideo , Ishijima Tatsuo , Hotta Hirotaka
Published: October 2013

An experimental study was carried out to find the mechanism of OH spectra generation through sonoluminescence. Line spectra of OH, H, and O were observed very clearly in water vapor plasma generated by 2.45-GHz microwave irradiation under the pressure of 40 hPa; however, broadband continua were not detected. Multibubble sonoluminescence (MBSL) and single-bubble sonoluminescence (SBSL) have continua, and OH spectra were detected occasionally in MBSL. However, OH spectra were not detected in SBSL and higher temperature MBSL. The sources of emission in MBSL and SBSL were considered to be identical and differences in spectra of OH bands were attributable to the higher temperature. Experimental results obtained using low temperature water vapor plasma confirm that OH spectra depend on the bubble’s interior plasma temperature: that is, at low temperatures, spectra of OH (308 nm), Ha, Hb, and O are clearly visible in water vapor plasma.
Frequency effects on intense sonoluminescence and bubble dynamics in sulfuric acid
Authors: Hatanaka Shin-ichi , Hayashi Shigeo
Published: October 2013

Emission intensity increased remarkably with decreasing frequency for both multibubble sonoluminescence (MBSL) and single-bubble sonoluminescence (SBSL) in a concentrated sulfuric acid solution dissolving xenon gas. The spectrum of MBSL in the sulfuric acid showed the emission bands of a large peak at 388 nm and small peaks at 360 and 418 nm. The increase of MBSL intensity at lower frequency was responsible for the increase of the band peak at 388 nm in addition to the increase in continuous spectrum. The bubble dynamics in the sulfuric acid was different from that in water. The intense SBSL was emitted when the bubble was moving on an ellipselike trajectory. The intense MBSL was emitted even when multiple bubbles formed bubble clusters, which could not emit light in the water case.
Attempts to observe sonoluminescence from a single bubble driven at 10 MHz
Authors: Khalid Shahzad , Camara Carlos G. , Putterman Seth J.
Published: October 2013

A 10-MHz spherical transducer array is used to generate cavitation at its focus with a field of ∼100 atm. Sonoluminescence as well as light-scattering measurements will be discussed. [Research funded by DARPA.]
Dissociation of music and speech: Evidence from statistical learning in congenital amusia
Authors: Peretz Isabelle , Saffran Jenny
Published: October 2013

Individuals who suffer from congenital amusia (commonly called tone-deafness) have experienced life-long difficulties in processing of music. The deficit can be traced down to an impairment in fine-grained pitch discrimination [Hyde and Peretz, Psychol. Sci., (2004)]. Their language abilities appear intact. One possible account for this dissociation between music and speech is that amusics lack normal exposure to music because of their lifelong history of musical failures. In other words, amusics might be able to acquire basic musical abilities if given appropriate exposure. To test this possibility, a group of 11 adults with congenital amusia, and their matched controls, were exposed to a continuous stream of syllables or tones for at least 21 min. Their task was to try to identify words or motifs, defined by transitional probabilities, following the procedure used by Saffran and collaborators [Cognition, (1999) (2001)]. The results show that amusics can learn novel words as easily as controls whereas they systematically fail on musical materials. Thus, limited exposure cannot fully account for the musical disorder. Implications for the domain specificity/generality debate of statistical learning will be discussed.
Nonlinguistic rhythm perception depends on culture and reflects the rhythms of speech: Evidence from English and Japanese
Authors: Patel Aniruddh D. , Iversen John R. , Ohgushi Kengo
Published: October 2013

Does a listener’s native language influence the perception of nonverbal rhythms? One way to address this question is to examine the perception of rhythmic grouping, as suggested by Jakobson, Fant, and Halle in Preliminaries to Speech Analysis. Grouping refers to the perceptual clustering of events into higher level units such as phrases. Several principles of grouping of auditory patterns, established a century ago, have come to be thought of as innate properties of perception. The supporting data have come entirely from Western cultures, however. In this study, native English and Japanese speakers were tested for their perception of grouping in simple rhythmic sequences of tones. Members of the two cultures showed different patterns of perceptual grouping, demonstrating that basic auditory processes are shaped by culture. Furthermore, measurements of the temporal structure of English versus Japanese speech and music suggest that the observed differences reflect the rhythms of the two languages, rather than rhythmic differences between American and Japanese music. While it has long been known that a listener’s native language influences the perception of speech, these results suggest that native language can also exert an influence on general auditory perception at a basic level. [Supported by Neurosciences Research Foundation and by JSPS.]
Effects of musical experience on linguistic pitch perception training
Authors: Behne Dawn , Wang Yue , Ro/ Maren Helene , Hoff Ann-Karin , Knutsen Hans Andreas , Schmidt Marianne
Published: October 2013

Research continues to address the extent to which music ability transfers to other tasks and processes, among them speech perception. The current study examines the transfer of music experience to native and non-native linguistic pitch perception and tracks this process during training. Participants were nonmusicians (NMs) and music conservatory students (CMs), all of whom were native Norwegian listeners. Participants were tested with Norwegian and Mandarin materials in a tone-based and intonation-based directed attention dichotic listening task, administered five times during 2 weeks. Results show that training generally leads to increased accuracy in linguistic pitch perception. CMs are more accurate than NM in both tasks, and maintain this advantage throughout training. For both groups, training led to a decreased difference in performance between ears, with notably different patterns of ear improvement between NMs and CMs. Across languages, whereas CMs had improved accuracy in both tasks, NM showed no improvement in the tone task for either language. Findings indicate that musically trained listeners’ experience positively transfers to native and non-native linguistic pitch perception, an advantage which, in training, affords them more extensive improvement across linguistic pitch tasks and in particular for a non-native pitch task where the native linguistic system does not interfere.
A computer-assisted instruction system for self-teaching of discriminating Chinese tones based on their acoustical properties
Authors: Hiki Shizuo , Sunaoka Kazuko , Liu Song
Published: October 2013

A computer-assisted instruction (CAI) system for self-teaching to discriminate Chinese tones was developed, and provided through the internet to Japanese college students of Chinese language class. The data of acoustical analysis and perceptual judgment on the Chinese tones played an important role in designing the system. The result of observation on characteristic errors in discriminating Chinese tones by the Japanese students was also utilized. This system offered three kinds of use for self-teaching: testing, training, and reviewing. The original word lists consisted of 15 bisyllabic words with every combination of the four tones of Standard Chinese, involving different rates of unvoiced consonants, which disturbed the tone discrimination. In the partial word lists, only words having tone 2 and/or tone 3, which were difficult for the beginners, were excerpted from the original lists. Their speech samples with both female and male voices were accommodated. Temporal changes in fundamental frequency were extracted from the speech samples and displayed as visual cues in the training. It was also possible in the training to present only the words answered incorrectly in the preceding testing. By selecting suitable uses and word lists with the progress of self-teaching, the required time for achieving the goal was reduced.
The effects of training context on perceptual learning of accented speech
Authors: Duke Jessica E. , Sidaras Sabrina K.
Published: October 2013

This study investigates factors influencing adult listeners’ perceptual learning of talker-specific and accent-general properties of spoken language. Exposure to foreign accented speech under different training conditions was used to examine mechanisms involved in perceptual learning. Adult native speakers of American English were exposed to English words produced by six native-Spanish-speaking adults. During training, the Spanish-accented words were either grouped by speaker, by word, or were randomized with respect to speaker and word. The different types of training were hypothesized to direct attention to particular characteristics of the accented speech. At test, listeners were asked to transcribe novel words produced by familiar or unfamiliar accented speakers. Regardless of training condition, listeners who had been exposed to Spanish-accented speech during training were more accurate at test than an untrained control group. However, high variability training in which words were randomized led to better transcription performance at test than training with items grouped by speaker or by word. These findings suggest that high variability training may direct attention to the accent-general properties of speech necessary for perceptual learning of accented speech.
Acoustic correlates of accentedness and intelligibility of Spanish-accented English vowels
Authors: Nygaard Lynne C. , Sidaras Sabrina K. , Duke Jessica E. , Rasmussen Stig T.
Published: October 2013

The present study investigated the acoustic characteristics of English vowels produced by native speakers of Spanish and the relationship between the acoustic properties of non-native vowel production and perceived accentedness and intelligibility. Twelve native speakers of Spanish were recorded producing monosyllabic words in list format. Individual vowel tokens from a variety of consonant environments were identified and acoustic analyses were conducted, including measures of duration and formant (F1, F2, F3) frequency. Listener ratings of accentedness and intelligibility were obtained from a separate set of sentence-length utterances. The analyses showed that average overall vowel duration as well as the duration of individual vowels was positively correlated with judgments of accentedness and negatively correlated with overall sentence intelligibility. Speakers who were judged to be more accented and less intelligible produced vowels of longer duration than speakers who were judged to be less accented and more intelligible. Analyses of spectral characteristics and comparisons to native English speakers’ vowel productions will also be reported. These findings suggest that the temporal properties are one aspect of non-native vowel productions that significantly contribute to the perception of accentedness as well as to the overall intelligibility of individual native Spanish speakers.
Production and perception of American English vowels by native Japanese speakers
Authors: Nozawa Takeshi , Frieda Elaina M. , Wayland Ratree
Published: October 2013

Native speakers of Japanese (NJ) produced American English vowels in /CVC/ contexts. Twelve native speakers of American English listened to and identified the vowels in the Japanese speakers’ productions. In general, the vowels difficult for the NJ subjects to disambiguate in production were also difficult for them to differentiate in perception. An acoustic analysis revealed that the NJ speakers’ attempted /i/ and /■/ tokens and /■/ and /■/ tokens largely overlapped in the vowel space, but significant differences in duration were observed between their /i/ and /■/ tokens. These findings agree with the results of our previous studies. In our perception experiment, /■/-/■/ was the most difficult vowel contrast for the same group of NJ speakers to discriminate, and longer /i/ tokens were more correctly identified and shorter /i/ tokens were misidentified more often as /■/. In contrast to the perception experiment, the intelligibility of American English vowels produced by the NJ subjects was not affected by the place of articulation of the preceding consonant or by the voicing status of the following consonant. However, the American English vowels produced by the NJ subjects were less intelligible when a liquid /l/ follows, which may be attributed to their inability to produce /l/ authentically.
Phonetic disambiguation by Korean non-native speakers of English
Authors: Hwang Jiwon , Tserdanelis Giorgos
Published: October 2013

This study examined the effect of pragmatic contrast and auditory priming on the production of contrasts such as ‘‘mob∼mop’’ and ‘‘pat∼pet’’ by 22 Korean non-native speakers of English. Korean speakers played a card arrangement game with a native speaker of English (a confederate). In the pragmatic condition, critical items were arranged to enable the comparison of the same word (e.g. ‘‘mob’’) in two contexts, one where the situation might force subjects to make the contrast of mob and mop and one where the situation facilitates the confederates recognition of mob because there is no contrasting form. An additional auditory priming condition was induced by the confederate saying a phonetically similar word such as ‘‘what is below hob?’’ before the target ‘‘mob.’’ Koreans produced more English-like forms when they had to be distinguished from the contrastive item or when they had been auditorily primed. For both b/p and ae/E contrasts, vowel duration was used to signal the distinction in both conditions. Additionally, for the b/p contrast, closure voicing percentage was significantly longer but only in the pragmatic condition. Overall both conditions have similar disambiguating effect, but have different specific consequences for cueing consonant versus vowel contrasts.
Phonetic similarities between English and Korean sibilants: Implications for second language acquisition
Authors: Cheon Sang Yee
Published: October 2013

Recent models of L2 acquisition suggest that foreign accent is determined by the degree of articulatory, acoustic, and perceptual similarity between L1 and L2 sounds. This study examined cross-language perceptual and acoustic similarities between Korean and English voiceless sibilant fricatives: Korean lax aspirated /s/ and tense unaspirated /s*/ versus English alveolar /s/ and palato-alveolar /■/. AX discrimination tests revealed that listeners perceived the non-native contrast in terms of their L1 sound system. To determine acoustic similarity among the fricatives, two acoustic parameters were measured: duration and spectral peak frequency. It was expected that the more acoustically similar two sounds were, the more they would be perceived as the same sound by listeners. However, disparate results were obtained for perceived similarity and acoustic similarity. For instance, Korean lax /s/ and English /■/ before /i/ are acoustically similar, but listeners were easily able to discriminate between them. Perceptual similarity predicts ease of acquisition better than acoustic similarity because a listener’s perceptual system incorporates how the sounds are organized in their L1 phonological system. Language teachers need to consider not just degree of similarity between pairs of sounds, but also the differences between the L1 and L2 sound systems as a whole.
Vowel perception in second language acquisition
Authors: Garcia Bayonas Mariche
Published: October 2013

This study investigates the perception of ten English and five Spanish vowels by native-speakers (NS) and learners (L) at two levels of acquisition, and compares these vowels cross-linguistically. Research on the acquisition of vowels indicates that learners can improve their perception with exposure to the second language (L2) [Bohn and Flege (1990)]. Using Flege’s (1995) Speech Learning Model as a theoretical framework, this investigation incorporated a method of adjustment (MOA) task [Johnson et al., (1993)] used to analyze NS perception and production data, to add the dimension of the L2 learner data. The research question was: Are vowels selected differently by NS and L in an MOA task depending on level of proficiency? Spanish learners (n=40) and English learners (n=80) completed MOA tasks in which they were exposed to 120 synthetically produced vowels to analyze spectral variation in the acquisition of both sound systems, and how the learners vowel system may vary from that of the NS. In the MOA tasks they were asked to select which synthesized vowel sounds most resembled the ones whose spelling was presented to them. Results indicated that vowels are selected differently by NS and L, but there are differences among vowels.
Multidimensional category-goodness-difference assimilation of Canadian English /i/ and /ɪ/ to Spanish /i/
Authors: Morrison Geoffrey Stewart
Published: October 2013

Morrison [J. Acoust. Soc. Am., 117, 2401 (2005)] theorized that L1-Spanish learners of English initially identify the Canadian English /i/-/■/ contrast via a multidimensional category-goodness-difference assimilation to Spanish /i/, with more-Spanish-/i/-like vowels (shorter vowels, lower F1 and higher F2) labelled as English /■/ and less-Spanish-/i/-like vowels (longer vowels, higher F1 and lower F2) labelled as English /i/. The L1-Spanish listeners’ use of duration is positively correlated with L1-English speakers’ productions, but their use of spectral cues is negatively correlated; hence, exposure to English results in increased use of duration cues and reduced use of spectral cues, leading to unidimensional duration-based perception. Since, in L1-English speakers’ productions, spectral properties are partially correlated with duration properties, L2-English learners can use duration-based perception as a bootstrap for learning L1-English-like spectral-based perception. Results from a new study are presented. Unlike the previous study, synthetic stimuli in the new study included vowel inherent spectral change (VISC). Results were consistent with the theory above: Vowels that were poor matches for Spanish /i/ because they had converging-VISC were labelled as English /i/, and vowels with no VISC were labelled as English /■/. [Work supported by SSHRC.]
Multiple cue interpretation in non-native phoneme perception: Korean listeners’ perception of English /s/ in varied prosodic contexts
Authors: Kim Miran
Published: October 2013

This paper investigates prosodic influences on the non-native perception of English /s/ by Korean listeners, whose phonemic system includes a two-way distinction of fricative, plain /s/ vs. fortis /s*/. English stimuli varied in lexical stress and prosodic domain appear to be relevant to the Korean listeners perceptual responses such that more /s*/ responses to stimuli are obtained with more strengthening effects such as lexical stressed and phrase boundary initial position. Analyses of the relation between the spectral properties of the stimuli and perception shows that prosodic effects on /sV(C)/ syllables are compatible with the characteristics that have been reported as critical attributes in the distinction of plain and fortis fricatives in Korean. Spectral measurements include F0, H1-H2 (dB), and H1-F2 (dB) values of postfricative vowels, together with the spectral characteristics of frication noise. The relation between prosodic strength in the stimuli and Koreans /s-s*/ perceptual responses implies that Korean listeners interpret prosodic information associated with English /s/ as a part of the segmental properties of English /s/ instead of attributing them to prosodic effects. This leads us to conclude that phonetic information is not limited to a segment-to-segment or prosody-to-prosody transmission, but it can be overlapped in multiple phonetic dimensions.
Identification of English consonants by Korean students
Authors: Yang Byunggon
Published: October 2013

Previous studies have shown that Korean students have difficulty identifying some English consonants that are not in the Korean sound inventory. The aim of this study was to examine the accuracy score of English consonants correctly identified by 130 college students in order to find out English consonants with listening problems for the Korean students. The subject’s task was to identify one of the minimal pairs played in a quiet laboratory classroom. One hundred minimal pairs consisted of syllables with various onsets or codas: stops, fricatives, affricates, liquids, and nasals. Results were as follows: First, types of the correctly identified English consonants varied according to the level of each student’s total score. Second, the lower the group level, the lower the accuracy score for each consonant group divided by its manner. Third, those consonants in coda position of the test words were more difficult for the students to identify than those in onset position. Fourth, the subjects showed lower accuracy in the perception of any contrast with a fricative onset or coda. Finally, the students still had problems telling voiced from voiceless consonants, especially in coda position. Future studies will focus on examining students’ production data to trace their listening problems.
Asymmetry in discrimination of an American English contrast, /l-r/, by adult Japanese learners of English
Authors: Tsushima Teruaki
Published: October 2013

The present study provided further evidence on an asymmetry in discrimination of an American English contrast, /l-r/, by Japanese listeners. Experiment 1 (N=14) examined stimulus order effects in discrimination of the contrast in the AX discrimination procedure with an ISI of 300 and 1500 ms, using naturally produced stimuli. The results showed discrimination accuracy was significantly lower when /l/ was followed by /r/ than otherwise, under the ISI of 1500 ms. Experiment 2 (N=17) examined whether discrimination significantly differed when a typical /l/ was paired with an ambiguous /r/ and vice versa, using synthesized stimuli from a ten-step continuum (i.e., stimulus 1-7 and 4-10). The participants were tested on their identification of the stimuli, and discrimination of the stimulus pairs with the ISI of 300 and 1500 ms. The discrimination sensitivity (i.e., d′), based on the identification performance, was not significantly different between the two pairs. In the discrimination test, however, the sensitivity was significantly lower in the pair including the typical /l/ than in the other, under the ISI of 1500 ms. The results support the hypothesis that categorization of a relatively nativelike speech stimulus (i.e., /l/) in a discrimination task may induce some perceptual assimilation process.
Perceptual cue learning
Authors: McGuire Grant
Published: October 2013

This paper describes results from an on-going perceptual training study in which native listeners of English are trained perceive a categorical difference between Polish alveopalatal and retroflex sibilants. The stimuli consist of naturally produced, modified two-dimensional stimuli varying by fricative noise and formant transition cues. Subjects are trained to categorize using only the fricative dimension, formant transition dimension, or both dimensions. Testing consists of a two-alternative forced-choice discrimination paradigm and stimulus labeling. Initial results from pilot work and subjects in the fricative dimension training group demonstrate that some listeners can easily attend to either dimension independently for categorization where training focuses attention and sharpens boundaries while others rely heavily on the vocalic cues, only attending reliably to frication noise cues with several training sessions or through verbal instruction. A handful of subjects did not show any improvement due to training; most of these subjects also showed no initial categorization strategy. Moreover, sensitivity to the fricative dimension and boundary increases for all learners (measured in d′), with no corresponding increase or decrease in sensitivity to vocalic cues. Further results from other training conditions will also be reported. [Work supported by NIH-NIDCD.]
Cantonese and Japanese listeners’ processing of Russian onset and coda stops
Authors: Kochetov Alexei , So Connie K. , Carter Nicole
Published: October 2013

The study investigated influences of native phonological and phonetic knowledge on Cantonese and Japanese listeners’ processing of non-native stop consonants. Phonologically, Cantonese Chinese has a three-way place contrast in stops in onset and coda positions; Japanese has a similar contrast, however, only in onset position. Phonetically, Cantonese coda stops are acoustically unreleased; Japanese stops followed by devoiced vowels are acoustically similar to released coda stops in other languages, such as Russian. Two groups of listeners, native speakers of Hong-Kong Cantonese and Japanese, were presented with sequences of Russian voiceless stops (VC1♯C2V, where C1/C2=/p/, /t/, or /k/). Two tasks were employed: (i) identification of onset or coda stops and (ii) discrimination of sequences that differed in either onset or coda consonant. Both groups performed equally well in the identification and discrimination of onset stops. However, Japanese listeners performed significantly better than Cantonese listeners in the identification and discrimination of coda stops. The findings suggest that in non-native listening, the low-level native phonetic knowledge—the acoustic realization of stop place contrasts—can override the higher-level phonological knowledge—syllable structure constraints on the distribution of place features. [Work supported by Social Sciences and Humanities Research Council of Canada.]
Relationships between the intelligibility and acoustic properties of native English and Mandarin-accented English
Authors: Hayes-Harb Rachel , Smith Bruce , Bent Tessa , Bradlow Ann
Published: October 2013

Studies examining effects of talkers’ and listeners’ linguistic backgrounds on speech intelligibility have produced mixed results, and relatively little is known about which acoustic-phonetic features of native and non-native speech are responsible for many findings. These issues are addressed here via investigation of how acoustic properties of final consonant voicing contrasts influence word intelligibility. Native English and native Mandarin talkers’ productions of English words were presented in isolation to native English and native Mandarin listeners in an identification task. Intelligibility findings were related to preceding vowel duration, stop consonant duration, burst duration, and proportion of voicing during stop closure. As expected, native English listeners were more accurate identifying words spoken by native than non-native talkers. In contrast to previous findings of an interlanguage speech intelligibility benefit (ISIB) for sentences, non-native listeners found native speech more intelligible than non-native speech. However, non-native listeners found non-native speech more intelligible than did native listeners. For native talkers, all four acoustic measures contributed significantly to correct identification of voicing contrasts by both native and non-native listeners (with closure voicing most salient). In contrast, for non-native talkers, listeners tended to rely primarily on closure voicing and burst duration. Ramifications for ISIB will be discussed.
English listeners perceptual assimilations for Zulu sounds: Evidence in support of the articulatory organ hypothesis
Authors: Levitt Andrea , Best Catherine , Goldstein Louis , Carpenter Angela
Published: October 2013

The articulatory organ hypothesis predicts that listeners’ favored perceptual assimilations for non-native sounds will be native sounds that are produced by the same articulatory organ [L. Goldstein and C. Fowler in Phonetics and Phonology in Language Comprehension and Production, 159–207 (2003)]. Using discrimination paradigms, we tested English-speaking, adult listeners’ perceptual assimilations for four non-native Zulu consonants to see whether assimilations are stronger for sounds articulated with the same vocal-tract organ or those with the same constriction degree. For each Zulu sound, three possible English-language assimilations were provided: a best match, based on the most frequent consonant assimilation provided by the subjects in a previous study [C.T. Best, G.W. McRoberts, and E. Goodell, J. Acoust. Soc. Am. 109, 775–794 (2001)], an assimilation match where the consonant uses the same articulatory organ, and one where the consonant uses the same constriction degree as the Zulu target. For example, for the bilabial implosive, the best match was /b/ (same articulator and constriction degree), the same organ match /w/, and the same constriction match /d/. Although there were differences in the patterns of responses to the four sounds, overall the results provided support for the articulatory organ hypothesis predictions.
Acquisition of Japanese pitch-accent by non-native speakers
Authors: Kozasa Tomoko
Published: October 2013

Vowel duration and F0 movement in Japanese pitch-accented words produced by non-native speakers were investigated. Phonemic vowel length and pitch accent are two prosodic properties of Japanese that are problematic for language learners. The vowel length distinction is typically realized by durational differences, and pitch accent involves F0 movement from high to low within an accented word. Equal numbers of target words and filler words were produced by 50 speakers by repeating after audio recorded Japanese sentences one at a time. The stimulus sentences were uttered by a native speaker of Tokyo Japanese. Speakers were randomly divided into two groups. For group A, a visual stimulus indicating the native speaker’s pitch contour for the target word appeared right after each audio stimulus. Speakers were instructed to follow the visual stimulus as they produced the target word. No visual stimulus was provided to group B. A sufficient durational distinction between long and short vowels was produced by both groups. However, group B failed to produce adequate amount or direction of F0 movement. These results suggest that explicitly showing pitch contour to language learners improves their pronunciation of pitch accent.
Recognizing English words by Japanese speakers
Authors: Yoneyama Kiyoko
Published: October 2013

Japanese listeners are influence by word frequency and neighborhood density (Yoneyama, 2002) as in other languages such as English. Interestingly, non-native listeners are also affected by word frequency and neighborhood density when they recognize English (e.g., Bradlow and Pisoni, 1999; Imai et al., 2005). Based on the previous studies of neighborhood density by non-native listeners, Yoneyama (2006) investigated whether Japanese listeners learning English employ two types of lexical information (word frequency and neighborhood density) when they recognize English words, as in Imai et al. (2005). The results were different from the ones of Imai et al. (2005). Japanese listeners were sensitive to both probabilistic phonotactics and word frequency. A strong correlation between probabilistic phonotactics and neighborhood density still predict Japanese listeners can be influenced by neighborhood density in English word recognition. A critical difference between Yoneyama (2006) and Imai et al. (2005) is that they did not use the exact same materials, although Yoneyama (2005) selected the words as described in a conference paper of an earlier version of Imai et al. (2005). This study reports the results of the experiment in which the materials of Imai et al. (2005) were used.
Some current challenges in multichannel acoustic signal processing
Authors: Kellermann Walter
Published: October 2013

Hands-free human/machine communication involves major challenges for today’s state of the art signal processing if the humans should not be forced to carry or wear any technical gear and should be free to move. The spatial domain sampled by multiple loudspeakers for reproduction and multiple microphones for signal acquisition allows for spatialized listening experiences and for spatially selective acoustic scene analysis, respectively. Along with the possibility to serve several human communication partners simultaneously, such systems also introduce the need for localization algorithms. Three main types of impairment have to be addressed by signal processing algorithms to fulfill the promises of the general concept: first, acoustic feedback from the loudspeakers into the microphones; second, ambient noise and undesired pointlike interferers; and, finally, echoes and reverberation as picked up by the human ear when listening to the loudspeaker signals or as recorded by the microphones that actually should record only the direct-path component of the source signal. Accordingly, some of the current challenges in multichannel acoustic echo cancellation, in spatially selective noise and interference suppression, in source separation and localization, and in dereverberation are investigated.