bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of two-dimensional underwater particle velocity pickup sensor
Authors: Tianji Zhao
Published: November 2016

Addressing the subject of a suspended co-oscillating vector hydrophone application platform, a new sound wave receiving theory model of underwater particle velocity pickup sensor was established. Based on the study of the inner sound field of an elastic cylinder vibrating freely under the action of sound waves in theory, the influence of material and geometry parameters on the frequency response of particle velocity has been analyzed. According to the results of parameter optimization and taking into account engineering needs, one sample of two-dimensional particle velocity pickup sensor has been designed and tested. By comparing the results of sensitivity and directivity tested in a calibration device, the general rules of theoretical analysis have been verified. The theory and experiments confirmed the feasibility of particle velocity pickup sensors in engineering applications.
The impact of cochlear implantation on spatial hearing and listening effort
Authors: Litovsky Ruth , Misurelli Sara , Godar Shelly , Thakkar Tanvi , Kan Alan , Winn Matthew
Published: November 2016

We studied the potential benefits of bilateral hearing in cochlear implants (CI) users, and in patients with single-sided deafness (SSD) who receive a CI in the deaf ear and have normal hearing in the other ear. We hypothesized that listening effort, measured with pupil dilation, can reveal benefits of bilateral hearing that may not be consistently observed when localization or spatial release from masking (SRM) are measured. Result from 12 bilateral CI users showed reduction in listening effort with bilateral hearing compared to the poor ear or better ear alone. In patients with SSD, benefits of adding a CI to a normal hearing ear can emerge over a protracted period of a year or longer. In addition, for at least some of the subjects bilateral hearing (adding a CI to the normal hearing ear) produced release from listening effort even in conditions where SRM was not observed. That is, speech intelligibility did not always improve with spatial separation of target and competing speech, but pupil dilation was reduced, suggesting that pupillometry can reveal subtle aspects of bilateral benefits. The benefits shown with pupillometry are consistent with the patients’ subjective reports of improved ability to function in complex, noisy acoustic environments.
Interaural level difference processing as a function of frequency
Authors: Goupell Matthew J. , Rosen Beth
Published: November 2016

To localize in the azimuthal plane, humans utilize interaural time differences and interaural level differences (ILDs). For sounds presented in the free field at different azimuthal locations, ILDs generated by the head are complex functions that are frequency dependent and non-monotonic, and are thought to contribute towards sound localization primarily at frequencies above 1500 Hz. However, previous studies have shown that ILD sensitivity is relatively frequency independent for tones presented over headphones, even at frequencies below 1500 Hz. The purpose of this study was to carefully re-investigate the frequency dependency of ILD sensitivity in normal-hearing listeners. Ten normal-hearing listeners were presented ILDs using insert earphones at 31 frequencies between 100 and 11,000 Hz. A 20-dB range of level roving was used to limit listeners’ ability to use monaural level cues to perform the task. On average, ILD sensitivity had several high and low sensitivity frequency regions, was best at 7000 Hz (1.5 dB) and worst at 1000 Hz (2.5 dB). Individuals also showed some unique frequency dependent patterns. These results suggest that ILD sensitivity is frequency dependent and neural models of ILD processing need to accommodate this dependency.
Vowel duration before ejective stops
Authors: Beguš Gašper
Published: November 2016

It has been well established that vowels are phonetically longer before voiced than voiceless stops, all else being equal. To my knowledge, however, no studies have measured vowel durations before ejective stops. This paper aims to fill this gap: I present preliminary results from a phonetic experiment with nine speakers of Georgian, establishing for the first time that vowels are (i) significantly longer before ejective stops than before voiceless aspirated stops and (ii) significantly shorter before ejective stops than before voiced stops. While the dependent relationship between vowel duration and obstruent voicing is well known, the cause of this relationship is poorly understood. The results presented in this paper shed new light on our understanding of differences in vowel durations and, in doing so, render several proposed explanations for these differences considerably less likely. In particular, my results show that (i) the voice feature itself likely does not affect vowel duration, (ii) closure duration of the following stop is not inversely correlated with vowel duration, and (iii) perceptual factors likely play no role in determining vowel length. My study shows that laryngeal features are the best predictors of vowel duration, suggesting an articulatory connection between these two factors.
Tenseness in Northern Yi: An ultrasonic and acoustic study
Authors: Chen Shuwen , Lama Ziwo
Published: November 2016

A contrast between tense and lax vowels is a main feature of many Tibeto-Burman (TB) languages spoken in Southwest China. This study investigated the articulation and acoustics of tense-lax contrast in two Northern Yi dialects: Suondi and Yinuo. Both dialects have five pairs of phonologically-defined tense and lax vowels. Previous studies have shown that tense and lax vowels in TB had distinct patterns in phonation types and f0, while the difference in other acoustic dimensions—vowel quality, duration, and intensity are rarely examined, and the difference in the lingual gestures is largely unknown. The current study examined the articulatory and acoustic characteristics of tense-lax contrast using ultrasound imaging and spectrogram analysis. Our preliminary results showed that articulatorily, tense vowels were produced with more retracted tongue root. Acoustically, tense vowels had higher F1 and lower F2, which was caused by the lowered and retracted tongue position. The intensity of tense vowels was lower than that of lax vowels for front vowels. No significant difference was found in duration. Based on the articulatory and acoustic data, as well as the vowel harmony phenomenon in Yi, we propose that the tense-lax distinction in Northern Yi can be better represented as [+RTR] phonologically.
F0 and plosive voicing in Afrikaans
Authors: Coetzee Andries W. , Beddor Patrice S. , Bouavichith Dominique , Craft Justin T. , Wissing Daan
Published: November 2016

Afrikaans plosives are traditionally described as contrasting in voicing ([b d] vs. [p t]). Coetzee et al. (2014, J. Acoust. Soc. Am. 135, 2421), however, showed that the voicing contrast is collapsing word-initially, with voiced plosives merging with voiceless plosives. They also found that voicing loss does not result in loss of lexical contrast, which is preserved on the following vowel (high f0 after historically voiceless and low f0 after historically voiced plosives). That study investigated word-initial plosives, leaving unanswered whether word-medial plosives are also devoicing. The current study addresses this question. Acoustic analysis of data collected from nine Afrikaans speakers replicated the results of Coetzee et al. for word-initial plosives. For word-medial plosives, a robust voicing contrast was found along with a post-plosive f0 difference. The f0 difference in medial position was comparable to that in initial position in both magnitude and duration, and extended throughout the vowel. While lexical contrasts are hence cued by only f0 word initially, they are differentiated by both plosive voicing and the f0 of the following vowel word medially. The relevance of these results for theories of sound change and theories of phonological contrast will be discussed. [Work supported by NSF.]
Method for recognizing multiple emotions from acoustic features using soft clustering
Authors: Uemura Joji , Mera Kazuya , Kurosawa Yoshiaki , Takezawa Toshiyuki
Published: November 2016

When a speaker expresses multiple emotions at the same time, emotion recognition methods using multi-class classification cannot recognize all the emotions because they always choose “an” emotion class. We thus propose a method to recognize multiple emotions expressed in parallel by using soft clustering (fuzzy c-means algorithm). Seven support vector machines for regression (SMOreg) calculate element values of the data. The SMOregs calculate probabilities of the following seven emotions: anger, anticipation, disgust, fear, joy, sadness, and surprise. First, 584 pieces of emotional voice data annotated with one of the seven emotions were used to calculate eight cluster centers on the basis of 384 acoustic features. Next, the characteristic of each cluster was defined on the basis of annotated tags of data belonging to the cluster. The characteristic was expressed in terms of valence (pleasure-displeasure) and arousal (high-low). To evaluate whether voice data that have two high membership grades have both emotion characteristics of the high-membership clusters, calculated membership grades were compared with the results of a questionnaire in which 10 subjects gave their impressions of the voices. We will show the experimental results and the comparison in the presentation.
For bilinguals, Enxet vowel spaces smaller than Spanish
Authors: Elliott John
Published: November 2016

This study compares the vowel spaces of bilingual speakers of Spanish and Enxet Sur (ISO 639-3: enx), a moderately threatened language spoken by around 4000 speakers in the Paraguayan Chaco which purportedly lacks high vowels. The Enxet vowel system has only three phonemic vowel qualities /e,a,o/ and a length distinction. Using recorded natural speech data from two Enxet/Spanish bilinguals, formant values for vowel tokens are used to establish phonetic targets and acoustic vowel clouds for each of the phonemic vowels in both languages. A comparison of these vowel spaces suggests that an individual bilingual speaker uses a smaller vowel space when speaking Enxet (less vowel height, higher minimum F1 frequencies) than when speaking Spanish. Languages like Enxet lacking in true high vowels present problems for the theory of adaptive dispersion in that they do not “take advantage” of maximal distinctiveness in the acoustic and articulatory quality of their vowels. This is the first known phonetic investigation of an Enlhet-Enenlhet language.
Temporal organization of onglides in standard Chinese and Taiwanese Mandarin: A cross-dialectal study
Authors: Hsieh Feng-fan , Li Guan-sheng , Chang Yueh-chin
Published: November 2016

This study examines the temporal organization of prenuclear glide (onglide) gestures within a syllable. Kinematic data were collected from four Standard Chinese (SC) and four Taiwanese Mandarin (TM) speakers using an NDI Wave. Mean relative timing of C/G gestures to a (heterosyllabic) consonantal anchor /p/ were calculated using the lag between achievement of constriction of the C/G and /p/. By comparing a given subject’s mean lags for Cs/Gs with CGs, we calculated the subject’s leftward (C vs. CG) and rightward (G vs. CG) shifts associated with /pj/ and /kw/. Results show that in SC, onglides /j/ and /w/ don’t pattern alike: for /kw/, all SC speakers show both leftward and rightward shifts (i.e. the C-center effect), except for subject S3, who fails to show a leftward shift (due to a different regional accent). For /pj/, only rightward shifts are found for all SC speakers. In contrast, regarding /kw/, only leftward shifts are found for all TM speakers, except for subject S8 (due to a different accent), while for /pj/, all TM speakers show rightward shifts, again, except for subject S8. Our findings thus suggest a cross-dialectal difference in /kw/ and confirm the possibility of the rightward shift in gestural coordination. Implications for the phonological status of onglides in Mandarin Chinese will also be discussed.
Acoustics of epenthetic vowels in Brazilian Portuguese
Authors: Kouneli Maria
Published: November 2016

In this production study involving a task of real words and a task of nonce words, epenthesis in obstruent-obstruent clusters in Brazilian Portuguese was investigated and the acoustic properties of epenthetic and lexical [i] were compared. A number of linguistic factors were found to be significant predictors of the epenthesis rate: voicing of the consonants of the cluster, manner of articulation of the second consonant, place of articulation of both consonants, and position of the cluster with respect to the stressed syllable. Moreover, there was a higher epenthesis rate for nonce words than for real words. As for the quality of the epenthetic vowel, it was found to have the same F1 as the lexical [i] in the language, but it was significantly shorter in duration, and it had a significantly lower F2 in the nonce words, but not in the real words. Finally, we found a relatively high rate of deletion of lexical [i], conditioned by the same factors that conditioned epenthesis rate, but in the opposite direction. It is concluded that epenthesis is a phonological phenomenon in Brazilian Portuguese, but that there is also acoustic reduction in the language that affects both lexical and epenthetic vowels.
Articulatory correlates of /w/ in Korean
Authors: Kwon Soohyun
Published: November 2016

The articulatory properties of /w/ have received relatively little attention compared to those of vowels and consonants. Although lip protrusion as well as dorsum raising and backing have generally been considered the major articulatory correlates of /w/, there is cross-linguistic evidence that the primary articulation of labiovelars, including /w/, is labial in some languages, while in other languages it is velar ([1]). Partly due to little articulatory data, there is little consensus on what articulatory features are involved in the production of /w/ in each language. This study used ultrasound to image tongue shapes for /w/ produced by three native Korean speakers. Also, a video camera was used to capture the movement of lips. The video data of movements of both tongue and lips were subjected to Optical Flow Analysis, a technique used to measure the magnitude of movement (MM) of objects in a video. The results show that there is prominent lip protrusion gestures for /w/ in Korean while there is little movement in tongue dorsum (the average MM of lip = 1.78; tongue = 0.48; t(86) = 4.02, p<0.001). This finding indicates that the glide /w/ in Korean involves labial movements only, contrary to the previous description of Korean glides [2], [3].
Tongue body shape during the production of Irish palatalization and velarization
Authors: McGuire Grant L. , Padgett Jaye , Bennett Ryan , Ní Chiosáin Máire , Bellik Jennifer
Published: November 2016

Irish is an endangered Celtic (Goidelic) language that has a rare phonemic contrast between palatalized and velarized consonants for all places and manners of articulation. Using ultrasound tongue body imaging of 15 native speakers we provide comparative data on the phonetic realization of the contrast, specifically focusing on how place, manner, and vowel context each affect tongue body position during production for each of the three major dialects. Using principal components analysis, we find evidence for the role of tongue root advancement in the contrast independent of the (less surprising) roles of tongue body frontness and raising. This data have consequences for our understanding of the relationship between phonetic and phonological categories as well as the role of perceptual saliency in shaping inventories.
Gradient phonemic contrast in Nanjing Mandarin
Authors: Johnson Keith , SONG Yidan
Published: November 2016

The variety of Mandarin Chinese spoken in Nanjing does not have a contrast between [n] and [l]. The standard variety of Mandarin which is now taught in schools in Nanjing does have the contrast. Prior research has shown that listeners' subjective impression of sound similarity is modulated by linguistic experience. When sounds are contrastive in a language they sound more different than when they are not contrastive. We conducted an experiment to test the subjective perceptual consequences of lack of [n]/[l] contrast in Nanjing, and of learning the standard variety of Mandarin in school. The stimuli were seven instances each of [tana] [tala] and [tara]. The listeners were 16 younger (< 45 yrs) and 16 older speakers of Nanjing Mandarin, and 35 speakers of American English. The listeners' task was to rate on a 5 point scale their subjective impression of the difference between the words (1 = similar, 5 = different). For American English listeners [l]/[r] pairs and [n]/[r] pairs were rated as different (3.8) while [n]/[l] pairs were heard as a little more similar than this (3.3). For older Nanjing Mandarin speakers [l]/[r] and [n]/[r] pairs were very different (4.8) and [n]/[l] pairs were very similar (1.5). Younger Nanjing Mandarin speakers also rated [l]/[r] and [n]/[r] pairs as very different (4.6), while the [n]/[l] pairs were not as similar (2.25) (standard errors < 0.1). Exposure to a non-native phonological contrast seems to have perceptually enhanced it gradiently.
A classification method for crowded situation using environmental sounds based on Gaussian mixture model-universal background model
Authors: Tanaka Tomoyasu , Hara Sunao , Abe Masanobu
Published: November 2016

This paper presents a method to classify a situation of being crowded with people using environmental sounds that are collected by smartphones. A final goal of the research is to estimate “crowd-density” using only environmental sounds collect by smartphones. Advantages of the approach are (1) acoustic singles can be collected and processed at low cost, (2) because many people carry smartphones, crowd-density can be obtained not only from many places, but also at any time. As the first step, in this paper, we tried to classify “a situation of being crowded with people.” We collected environmental sounds using smartphones both in residential area and downtown area. The total duration of the collected data is 77,900 seconds. The sound of “crowded with people” is defined as buzz-buzz where more than one person talked at the same time. Two kinds of classifiers were trained on the basis of the GMM-UBM (Gaussian Mixture Model and Universal Background Model) method. The one was trained with acoustic features that are generally used in speech recognition, and the other was trained with additional parameter of sound power. Experiment results showed that the parameter of sound power improves the F-measure to 0.60 from 0.58.
An ultrasound study of the nasal substitution in Javanese
Authors: Qin Lang
Published: November 2016

Nasal substitution in Austronesian languages refers to replacement of voiceless obstruents by homorganic nasals under certain morphological conditions. In Javanese, for example, the active form of verb [tuku] “buy” is [nuku] and that of [tʃakar] “scratch” is [ɲakar]. However, exception does exist; namely, the sibilant [s] is paired with a palatal nasal [ɲ], e.g., the active form of [sawaŋ] “see” is [ɲawaŋ]. This ultrasound study aims to verify: i) whether the perception of two distinct places of articulation ([s]/[ɲ]) is matched in the articulation, suggesting an abstract relation between the two sounds, ii) or whether the homorganic pattern seen elsewhere in this morphological paradigm is matched in the articulation, suggesting a concrete relation between the two sounds. SS ANOVA results based on data of 8 Javanese speakers reveal that tongue position of /s/ bears more resemblance to /t/ and its nasal counterpart /n/, whereas the the tongue position of the nasal counterpart of /s/ is more posterior and closer to that of /tʃ/ and its nasal counterpart /ɲ/, which supports the abstract relation between [s] and [ɲ].
Relative fundamental frequency of voiced and voiceless stops and fricatives for different phonation types in normal French speakers
Authors: Robieux Camille F. , Meunier Christine
Published: November 2016

The relative fundamental frequency (RFF) was recently used to assess vocal effort in normal and dysphonic subjects since it reflects the vocal fold tension at the offset and onset of vowels with, in particular, lower values at the edges of voiced consonants compared to their voiceless counterparts. In this study, we explored the RFF variations according to the voicing status and the articulation manner of consonants, in several types of speech production known to involve different levels of vocal effort. Twelve native French speakers (6 females) with normal voice were asked to produce 24 trains of eight syllables in seven vocal conditions: spontaneous, low, high, soft, loud, breathy, and pressed voice. We considered the unaspirated voiceless and voiced consonants /p, b, f, v/ with the middle open vowel /a/. As expected, the RFF was lower for voiced than for voiceless consonants. In addition, it was lower for stops than for fricatives. The RFF was also lower for the high, loud, and pressed conditions while it was higher for the low, soft, and breathy conditions in comparison to the values for the spontaneous voice. The RFF measurement seems to be efficient to discern subtle levels of vocal effort in normal subjects.
Preliminary study on physiological contrasts between long and short vowels in Japanese
Authors: Shirose Ayako , Nota Yukiko , Kitamura Tatsuya
Published: November 2016

The purpose of this study is to identify physiological contrasts between long and short vowels in Japanese. Japanese (Tokyo Japanese; TJ) is known as a mora-timed language. Durational length of vowels and consonants, short or long, is used to discriminate between words in Japanese; in one example, kabu, “bottom,” and ka:bu, “curve,” are distinguished by Japanese speakers. Previous studies have discussed the durational contrasts acoustically and phonologically; however, an articulatory explanation was not taken into account. In order to understand the articulatory process of durational contrasts, we analyzed movements of the lips and tongue using an electromagnetic articulography (the NDI Wave Speech Research System). Two TJ speakers were asked to produce minimal pairs of words including short or long vowels (e.g., kabu-ka:bu, koto-ko:to). The position of six sensors attached on their lips and tongue was tracked during the speech. The sensors were placed on the upper and lower lips, right angular of the lip and the tongue dorsum. Analysis of the data revealed that the lower lip and posterior tongue moved downward more in articulating long vowels than short vowels. This result suggested that long vowels caused not only acoustic and phonological lengthening of syllable duration, but also overlapping of articulatory movements.
Hejazi Saudi Arabic pharyngeal approximant 'Ayn involves 4 of 5 correlates of creak, but not positive H1-H2 spectral tilt
Authors: Thorne James M.
Published: November 2016

Five correlates of creaky phonation in the Arabic pharyngeal approximant 'Ayn—/ʕ/—were compared in speech samples of five male native speakers of the Hejazi dialect of Saudi Arabic to determine the degree to which creaky phonation could be a phonetic feature of 'Ayn. Jitter, shimmer, harmonics-to-noise ratio (HNR), F0 lowering, and positive H1-H2 spectral tilt were compared in 360 (total) speech tokens of /a/, /aa/, and /aʕa/ vowel sequences. Acoustic analysis indicated significantly increased jitter, increased shimmer, lower HNR, and lower F0 values in 'Ayn sequences compared to non-'Ayn sequences, yielding strong evidence of creaky phonation. There was, however, no significant increase in degree of positive H1-H2 spectral tilt in 'Ayn sequences compared to non-'Ayn sequences. Positive tilt appeared to occur in free variation across vowel sequence types with many non-'Ayn sequences displaying the positive H1-H2 spectral tilt traditionally associated with creak. If increased jitter, increased shimmer, lower HNR, and local F0 lowering are correlates of creak in these realizations of 'Ayn, we must consider that creak is a key phonetic feature of 'Ayn for these Arabic speakers and that positive H1-H2 spectral tilt may not be a reliable indicator of creak in Hejazi Arabic.
Talker variability and the use of perceptual cues in Hong Kong Cantonese lingual stop codas
Authors: Yip Jonathan C.
Published: November 2016

Cantonese inaudibly released oral stop codas, whose place cues occur only before constriction and not during or after constriction, appear to be merging among young-adult speakers (Law, Fung, & Bauer, 2001). Prior work (Yip, 2015) revealed substantial articulatory variation among five talkers, ranging from gestural preservation, to coproduction of lingual-lingual sequences, to gestural loss. Coda contrasts were cued by first- and third-formant loci (both lower into /k/ than into /t/) and preceding vowel duration (longer before /t/ than before /k/). In the present study, 18 Cantonese-speaking listeners’ perception of codas produced by talkers in the prior study was tested in an AXB task in which ambiguous coda productions were judged as more similar to each talker’s best coda /t/ or /k/ production, as assessed with ultrasound tongue imaging. Comparisons of listener sensitivity to cues—based on LMER estimates for change in accuracy with respect to relevant acoustic response variables—with their accuracy rates for individual talkers indicate that listeners who were sensitive to particular acoustic cues gained a perceptual advantage for talkers who produced those cues. However, greater articulatory achievement in the stimuli did not correlate with better perception, except for productions by talker T4, who produced gestural loss.
Acoustic evidence for prosodic units in Navajo
Authors: Palakurthy Kayla
Published: November 2016

Although prosody and intonation are generally considered to be linguistic universals, the few prosodic studies of Navajo, a Southern Athabaskan language spoken in the American Southwest, report a lack of meaningful intonation (McDonough 1999; McDonough 2002). This paper revisits the question of Navajo prosody, presenting the results of a quantitative analysis of acoustic correlates of prosodic constituents in personal narratives. Building on previous studies of Athabaskan prosody (Berez 2011; Lovick and Tuttle 2012), the present work employs mixed-effects linear modeling to examine pitch (F0) reset and syllable and pause duration at different prosodic and syntactic boundaries. Results provide evidence for both intonational units marked by final syllable lengthening and also larger prosodic sentences cued by pauses and pitch reset. Furthermore, the demarcation of prosodic units is statistically more robust than clause boundaries, underscoring the orthogonal relationship between prosodic and syntactic structure. These data suggest that Navajo does have systematic prosody, but the cues may only be identifiable in larger stretches of connected speech, rather than individual words or phrases. Results are compared with other work in the small, but growing typological literature on intonational characteristics of large prosodic units.
Production and perception of the low vowels in American English
Authors: Fridland Valerie , Kendall Tyler
Published: November 2016

Two vowel features are especially pivotal in defining contemporary U.S. dialects: The merger of the low back vowels and the variable realizations of the low front vowel. Several scholars (Bigham 2010, Gordon 2005, Labov, Ash and Boberg 2006) suggest a relationship between the low front and low back vowels such that /æ/ raising and subsequent fronting of /ɑ/ in the North inhibits the tendency toward low back merger. However, little work examines the robustness of this “structural linkage” or whether a similar relationship obtains across different regional varieties. Further, little work examines whether differences in production correlate with differences in regional perception patterns. Here, we compare the low vowel system across U.S. regional dialects and also consider interrelationships (i.e., correlations) between low vowel categories using data from eight fieldsites across the U.S. We then look at what these speakers’ perceptions of category shift between the low front and low back vowel tells us about this relationship in production. Our results suggest both that the regional vowel shifts create significantly divergent low vowel systems across regions but also that /æ/ and /ɑ/ indeed show a structural linkage across regions, while /æ/ and /ɔ/ and /ɑ/ and /ɔ/ show no such relationship.
Phoneme distribution and syllable structure of entry words in the Carnegie Mellon University Pronouncing Dictionary
Authors: Yang Byunggon
Published: November 2016

This study explores the phoneme distribution and syllable structure of entry words in the CMU Pronouncing Dictionary to provide linguists with fundamental phonetic data on English word components. Entry words in the dictionary file were syllabified using an R script and examined to obtain the following results: First, English words preferred consonants to vowels in their word components. In addition, monophthongs occurred much more frequently than diphthongs. When all consonants were categorized by manner and place, the distribution indicated the frequency order of stops, fricatives, and nasals according to manner and that of alveolars, bilabials and velars according to place. Second, from the analysis of syllable structure, two-syllable words were most favored, followed by three- and one-syllable words. Of the words in the dictionary, 92.7% consisted of one, two, or three syllables. Third, the English words tended to exhibit discord between onset and coda consonants and between adjacent vowels. Dissimilarity between the last onset and the first coda was found in 93.3% of the syllables, while 91.6% of the adjacent vowels were different. The author concludes that an analysis of the phonetic symbols in a dictionary may lead to a deeper understanding of English word structures and components.
Improvement of sensor for electromagnetic articulograpy to reduce detrimental effects of sensor attachment on articulation
Authors: Nota Yukiko , Kitamura Tatsuya , Hashi Michiko , Hatano Hiroaki
Published: November 2016

Electromagnetic articulography (EMA) tracks the position and direction of small wired sensors attached inside and outside of the mouth during articulation. In this study, we improved a five degree-of-freedom sensor of the NDI Wave speech research system, which is a type of EMA system, to reduce the effects of sensor cable on articulation. This was done because the thickness and stiffness of the original cable appeared to interfere with natural articulation. The new cable has the diameter of 0.1 mm, which is thinner than the original, and is more flexible. The degree of interference due to sensor attachment to the articulators was evaluated by comparing the extent of distortion of speech produced by four elderly speakers with new and original sensor attached to their articulators. The speakers produced a Japanese vowel sequence and VCV sequences with the two types of sensors attached to their articulators, and three Japanese speech language pathologists evaluated their speech for the degree of speech distortion. The results suggest that the new sensors were much less likely to disturb natural articulation. [This research was partly supported by JSPS KAKENHI Grant Nos. 24652085, 25240026, and 25280066.]
Probabilistic simulation for analysis of quantal biomechanical-acoustic relations
Authors: Stavness Ian , Roewer-Despres Francois , Gick Bryan
Published: November 2016

Acoustic signals that are stable across a range of articulatory parameters have been suggested as an important feature of speech production [Stevens 1989, J. Phonetics, 17, 3-45]. These so-called quantal effects have also been suggested to arise from the biomechanics of the vocal tract [Fujimura 1989, J. Phonetics, 17, 87-90; Gick & Stavness 2013, Front Psychol 4, 977]. Assessment of potential biomechanical-acoustic quantal relations is hampered by the difficulty of measuring biomechanical parameters, such as muscle excitations, during speech production. Computer modeling has been widely used to probe vocal tract biomechanics, but previous modeling studies have been limited to a small number of deterministic simulations [Gick et al. 2014, CMBBE Imag Vis., 2, 217-22]. We propose a novel probabilistic simulation framework in order to assess how variation in speech motor signals manifests in acoustic variation. We use a detailed 3D biomechanical model of the vocal tract coupled to a source-filter acoustics model [Stavness et al. 2014, Siggraph Asia Tech, 9] in order to generate acoustic output from muscle excitation inputs. Monte Carlo sampling of muscle excitation inputs are used to characterize variation in formant frequencies for vowel production. These large-scale simulations permit us to evaluate the hypothesis that quantal acoustic signals originate from regions of biomechanical stability. If found, quantal biomechanical-acoustic relations would provide a simple, principled mechanism for feedforward control of speech production.
Acoustic features of prosodic boundary by Chinese learners of English as a second language
Authors: Zhang Yuanyuan , Ding Hongwei
Published: November 2016

The production and perception of prosodic boundary have been well studied in English, but the research regarding to English as a second language (L2) is sparse. It has been shown that Chinese and English employ different acoustic features to mark prosodic boundary in production. Thus, this study aims to find out whether the Chinese learners of English employ the same strategy to convey prosodic boundary in English as the native speakers do. Ten pairs of syntactically ambiguous utterances composed of two or three food items were designed, with 10 pairs of filler utterances half randomized together. Ten speakers (5 males and 5 females) from Shanghai who passed the annual national examination CET (College English Test) Band 6 were asked to read the utterances. The results showed that, similar to the native speakers, Chinese learners also use pre-boundary lengthening, pause duration and pitch reset to signal the prosodic boundary in English. However, their pitch contour of the pre-boundary syllable is falling under boundary condition, and is rising under non-boundary condition, which is opposite to that of the native English speakers. This result will have an implication in L2 English teaching and learning.
Spoken keyword detection using recurrent neural network language model
Authors: Koike Shuhei , Lee Akinobu
Published: November 2016

Recently, spoken keyword detection (SKD) systems that listen live audio and tries to capture user's utterances with specific keywords has been extensively studied, in order to realize a truly usable hands-free speech interface in our life: “Okay google” in Google products, “Hey, Siri” on Apple products and “Alexa” on Amazon Alexa / Amazon echo. Since the keyword detectors are typically built from large number of actually spoken keywords, they are irreplaceable and the users of such systems are forced to speak only the keyword they defined. On the other hand, a SKD method based on keyword-filler model using generic phoneme model and garbage filler sequence model is promising in that, since the acoustic pattern of the keyword will can be given as phoneme sequence, it is task-dependent and anyone can use his own keyword. In this study, an improvement of the latter method is studied. Recurrent neural network language model (RNNLM) is introduced as linguistic constraint for both filler-filler and filler-keyword instead of N-gram, and experimental result on actual spoken data for a spoken dialogue system showed that our method can improve the keyword detection performance.
Voice activity detection in movies using multi-class deep neural networks
Authors: Suga Ikumi , Yasuhara Ryu , Inoue Masashi , Kosaka Tetsuo
Published: November 2016

For automatic classification of movie genres, detection of the presence or absence of speech is useful. Hence, accurate voice activity detection (VAD) techniques are needed. However, it is difficult to detect speech segments accurately because there are many kinds of noises in movies. Recently, deep learning has received increased attention in the speech processing field. Some VAD techniques based on deep neural networks (DNNs) have been proposed for clean speech conditions and showed better performance than conventional methods. The aim of this study is to improve VAD performance for movies by using DNNs. Generally, VAD is considered to deal with a two-class classification problem, i.e., classification of speech and non-speech segments. However, diverse noises in movies make it difficult. Therefore, it is difficult to detect speech segments accurately by using two-class DNNs. To solve this problem, we propose the use of multi-class DNNs for VAD in movies. In the experiments, we evaluated the proposed method for two types of movies, i.e., conversation-centric (CC) and non-conversation-centric (NCC) movies. The proposed multi-class DNNs showed better performance than conventional DNNs. The results showed that the equal error rates (EERs) for CC and NCC were 7.74% and 2.94%, respectively.
Super-resolution in sound field recording and reproduction based on sparse representation
Authors: Koyama Shoichi , Murata Naoki , Saruwatari Hiroshi
Published: November 2016

Sound field recording and reproduction enables us to construct more realistic audio systems. In practical systems, sound pressure is obtained with microphones in a recording area, and then the sound field is reproduced with loudspeakers in a target area. Therefore, a signal conversion algorithm for obtaining the driving signals of the loudspeakers from the signals received by the microphones is necessary. Most of the current methods are based on the sound field analysis and synthesis in the spatial frequency domain. Although these methods make it possible for stable and efficient signal conversion, artifacts originating from spatial aliasing notably occur, which depends on the intervals of microphones and loudspeakers. We have proposed a signal conversion method based on sparse sound field decomposition, which enables sound field recording and reproduction above the spatial Nyquist frequency. By using sparse decomposition algorithms, the sound pressure distribution can be represented using a small number of fundamental solutions of the Helmholtz equation, such as Green's functions. Group sparse signal models are also required for accurate and robust decomposition. In this presentation, we reports on comparisons between several group sparse signal models and decomposition algorithms as well as their relation to reproduction performances.
Spectral broadening of acoustic tones generated by unmanned aerial vehicles in a turbulent atmosphere
Authors: Ostashev Vladimir E. , Wilson D. K. , Finn Anthony , Rogers Kevin , Barlas Emre
Published: November 2016

The acoustic spectrum emitted by unmanned aerial vehicles (UAVs) and other aircraft can be distorted by propagation through atmospheric turbulence. Since most UAVs are propeller-based, they generate a series of acoustic tones and harmonics. In this paper, spectral broadening of these tones due to atmospheric turbulence is studied. The broadening results from the combined Doppler effect of multiply scattered acoustic signals propagating in a non-stationary turbulent atmosphere. It can be assessed as a Fourier transform of the temporal coherence function of a monochromatic signal propagating in an atmosphere with spatial-temporal fluctuations in temperature and wind velocity. This temporal coherence was recently investigated [V. E. Ostashev, D. K. Wilson, S. N. Vecherin, and S. L. Collier, J. Acoust. Soc. Am. 136 (5), 2414–2431 (2014)] for the model of locally frozen turbulence. Based on these results, spectral broadening is calculated and analyzed for typical meteorological regimes of the atmospheric boundary layer and different flight trajectories of UAVs. Experimental results are presented and compared with theoretical predictions. Spectral broadening might also provide a means for remotely sensing atmospheric turbulence.
Acoustic detection results for a small unmanned aircraft system extrapolated over range
Authors: Goldman Geoffrey H.
Published: November 2016

Small unmanned aircraft systems (SUAS) are becoming cheaper with more advanced reconnaissance and surveillance capabilities. Low-cost sensors and countermunitions are needed to defeat this asymmetric threat. The first step is to detect SUAS using low-cost sensors such as an array of microphones with robust signal processing algorithms. An analysis of six detection algorithms was performed using acoustic data generated by a class I SUAS at ranges of 50 to 650 m and measured with a small tetrahedral microphone array with 20-cm length arms. The detection algorithms were based upon the peak power in delay-and-sum, filtered delay-and-sum, and adaptive delay-and-sum beamforming algorithms. To test the performance of the algorithms at longer ranges, the measured signal, modeled as target plus additive noise, was modified. First, the signal from the target was attenuated using Bass’s model and spherical attenuation, and then, the noise was adjusted to maintain an unbiased estimate of the measured power spectrum density function. Receiver operation characteristics (ROC) curves were generated and the performance of the algorithms as a function of range was evaluated.
Stepped FM acoustic signal design
Authors: Sullivan Edmund J.
Published: November 2016

The linear Frequency Modulated (LFM) signal is a means of providing a broadband signal with a short time duration. One of its main uses is in active sonar, where it provides enhanced target range resolution and improved performance against reverberation. Its generation can be simplified by approximating it using a so-called Stepped Frequency Modulated (SFM) signal, where the pulse is made up of a set of contiguous single frequency pulses. In its simplest form, the frequency of these pulses increases (or decreases) in a linear manner along the time history of the pulse. This paper presents a technique for designing a SFM pulse that best emulates its LFM counterpart in its detection performance. It is shown that if the time-bandwidth product of the LFM is BT, the number of pulses in the SFM that best emulates the LFM is equal to the nearest integer to the square root of BT. Values of N smaller than this reduce the detection performance and values larger than this provide no improvement in detection performance and indeed, can cause some reduction the performance, where this reduction varies erratically as N increases.
Bulk cavitation extent modeling: An energy-based approach
Authors: Esplin J. J. , Kim Benjamin J. , Kinzel Michael P. , Culver R. L.
Published: November 2016

Bulk cavitation is a phenomenon that occurs when a negative-pressure or tension wave causes a liquid to rupture, or cavitate, over space. It is a process which causes resident microbubbles to grow to many times their original size, forming a bubble cloud. Such bubble clouds are observed in shallow underwater explosions, where negative-pressure waves are formed after shock waves reflect off the water surface; they are also observed in shock wave lithotripsy, shock wave histotripsy, ultrasonic cleaning, and other applications. Models had been developed for predicting the size and shape of such bulk cavitation regions. This work introduces a model that accounts for energy “lost” to bulk cavitation which in turn influences the extent that is dependent on the rate at which the passing negative-pressure wave dissipates. In-laboratory underwater experiments utilizing a spark source for high-amplitude pressure pulse generation, hydrophones and high-speed videography validate the energy transfer from tension wave to bubble cloud formation. These experiments are supplemented by computational fluid dynamics simulations. A cavitation absorption coefficient is introduced and parameterized for accurate prediction of cloud extent.
The effects of external acoustic fields on a free-running supercavitating projectile
Authors: Cameron Peter J. , Doane John W. , Rogers Peter H.
Published: November 2016

Proliferation of supercavitating torpedoes has motivated research on countermeasures against them as well as on the fluid phenomenon which makes them possible. The goal of this research was to investigate an envisaged countermeasure, an acoustic field capable of slowing or diverting the weapon by disrupting the cavitation envelope. The research focused on the interactions between high pressure amplitude sound waves and a supercavity produced by a small free-flying projectile. The flight dynamics and cavity geometry measurements were compared to control experiments and theoretical considerations were made for evaluating the effects. Corrugations on the cavity/water interface caused by the pressure signal have been observed and characterized. Results also show that the accuracy of a supercavitating projectile can be adversely affected by the sound signal. This research concludes with results that indicate that it is acoustic cavitation in the medium surrounding the supercavity, caused by the high pressure amplitude sound, that is responsible for the reduced accuracy. A hypothesis has been presented addressing the means by which the acoustic cavitation could cause this effect. [Much of the content of this paper was published in J. Acoust. Soc. Am. 128, 3381-3392 (2010).]
Two types of propagations of nonlinear sound beams in nonuniform bubbly liquids
Authors: Kanagawa Tetsuya
Published: November 2016

Weakly nonlinear propagation of diffracted sound beams in nonuniform bubbly liquids is theoretically examined. The spatial distribution of the number density of the bubbles, initially in a quiescent state, is assumed to be a slowly varying function of the spatial coordinates; the amplitude of variation is assumed to be small compared to the mean number density. Two types of nonlinear wave equations for progressive quasi-plane beams in weakly nonuniform bubbly liquids are then systematically derived via the method of multiple scales. The diffraction effect is incorporated by adding a relation that scales the circular sound source diameter to the wavelength into the original set of scaling relations composed of nondimensional physical parameters. A set of basic equations for bubbly liquids is composed of the averaged equations of mass and momentum in a two-fluid model, the Keller equation for bubble wall, the equation of state for gas and liquid, the mass conservation equation inside the bubble, and the balance equation of normal stresses across the gas-liquid interface. As a result, two types of evolution equations, a nonlinear Schrödinger (NLS) equation including dissipation, diffraction, and nonuniform effects for high-frequency short-wavelength case, and a Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation including dispersion and nonuniform effects for low-frequency long-wavelength case, are derived from the basic set. Finally, numerical and analytical solutions of NLS and KZK equations toward some applications are presented.