bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychoacoustic considerations in hearing aid design and fitting
Authors: Edwards Brent
Published: April 2018

Hearing aid technology has advanced tremendously over the past two decades, with multiple technologies introduced to improve the hearing of wearers with hearing loss. While hearing science has informed their development, the design of these technologies and their fitting have been approached primarily from a speech-centric perspective. This talk will reflect on hearing aid technology from the perspective of the type of fundamental psychoacoustic research conducted by Neal Viemeister throughout his career. Additional psychoacoustic research that is needed to inform future hearing aid designs will also be identified. A cookie will be bet that Neal is surprised by the relationship between psychoacoustics and hearing aid design.
Loudness of an auditory scene
Authors: Yost William
Published: April 2018

When multiple sound sources, each of equal level, are added together to create an auditory scene, the overall level of the scene grows with the increased number of sources despite the fact that the level of the individual sound sources remains the same. This experiment addresses a simple question: how does the overall perceived loudness of an auditory scene change as the number of sound sources in the scene changes. Sixteen Consonant-Vowels (CVs), spoken by ten males and ten females, were the sound stimuli. The CVs could be concatenated to produce nonsense “words” of different lengths. Different number (“n”) of concatenated CVs could be presented at one time from a single loudspeaker located on the azimuth plane or from different loudspeakers. Listeners determined if “n + delta n” sound sources were louder than “n” sound sources. The individual levels of the concatenated CVs was another independent variable. Preliminary data suggest that when “n” is small (<4), the level of the individual sounds determines loudness judgements. When n is larger (n>4) the overall level of the simultaneously presented sounds determines loudness judgements. A full study will be presented. (Work supported by grants from NIDCD and Oculus VR, LLC.)
Predicting speech intelligibility based on the modulation spectrum and modulation frequency selectivity
Authors: Dau Torsten
Published: April 2018

Speech intelligibility depends on factors related to the auditory processes involved in sound perception as well as on the acoustic properties of the sound entering the ear. A clear understanding of speech perception in complex acoustic conditions remains a challenge. Here, a computational modeling framework is presented that attempts to predict the speech intelligibility obtained by normal-hearing and hearing-impaired listeners in various adverse conditions. The model combines the concept of envelope frequency selectivity in the auditory processing of the sound with a decision metric that is based either on the signal-to-noise envelope power ratio or a correlation measure. The proposed model is able to account for the effects of stationary background noise, reverberation, nonlinear distortions and noise reduction processing on speech intelligibility. However, due to its simplified auditory preprocessing stages, the model fails to account for the consequences of individual hearing loss on intelligibility. To address this, physiologically inspired extensions of the auditory preprocessing in the model are combined with the modulation-frequency selective processing and the back-end processing that have been successful in the conditions tested with normal-hearing listeners. The goal is to disentangle the consequences of different types of hearing deficits on speech intelligibility in a given acoustic scenario.
Non-reciprocal wave phenomena through pump-signal wave interaction in discrete systems with asymmetric subwavelength geometry
Authors: Wallen Samuel P. , Goldsberry Benjamin M. , Haberman Michael R.
Published: April 2018

Acoustic non-reciprocity has been shown to enable a plethora of effects analogous to phenomena seen in quantum physics and electromagnetics, such as immunity from back-scattering, unidirectional band gaps, and topologically protected states, which could lead to the design of direction-dependent acoustic devices. One class of material that holds promise as a means to achieve acoustic non-reciprocity is the “Willis medium,” which exhibits strain-momentum coupling owing to asymmetry and non-local effects in the material microstructure. This work considers a method for obtaining non-reciprocal elastic wave propagation in a system with sub-wavelength asymmetry inspired by asymmetric Willis microstructures. Non-reciprocity is achieved through application of a slowly-varying pump wave that acts as a spatio-temporal modulation of the material, which is modeled as a discrete system with geometric nonlinearity. The modulation generates momentum bias for a fast-varying signal wave with pump-signal interaction enabled by weak nonlinearity associated with the variation of subwavelength asymmetric geometry. It is shown that momentum bias may be generated with a pump wave acting transverse to the direction of propagation, which may facilitate experimental realizations. [This work was supported by the National Science Foundation.]
Formant pattern and spectral shape ambiguity in vowel synthesis: The role of fundamental frequency and formant amplitude
Authors: Kathiresan Thayabaran , Maurer Dieter , Suter Heidy , Dellwo Volker
Published: April 2018

When investigating formant pattern and spectral shape ambiguity in Klatt synthesis, an earlier study showed that the perceived vowel quality of Standard German vowel sounds can be changed by varying fundamental frequency only [Maurer et al. (2017). J. Acoust. Soc. Am. 141(5):3469-3470]. In this follow-up study, the previous original synthesis experiment was repeated twice, firstly, with fundamental frequencies (fo) of the corresponding sounds lowered by one octave, and secondly, with different ratios of the first and second formant amplitudes. Here, the role of the fo range and the formant amplitudes for the investigation of formant pattern and spectral shape ambiguity in vowel synthesis was further examined. The same five phonetic expert listeners that participated in the previous experiment also identified all of the newly synthesised sounds in a multiple-choice identification task. Results revealed that the perceived vowel quality only changes for fos above 200 Hz and that, for back vowels, the ratio of the formant amplitudes used in the Klatt synthesis also affects vowel recognition. Thus, the results of the experiments confirm earlier indications of a non-systematic relation between fo or pitch and formant patterns or spectral envelopes for vowel recognition.
Electrophysiological measures of listening effort and comprehension: Speech in noise, vocoders, and competing talkers
Authors: Exenberger Anna , Iverson Paul
Published: April 2018

This study explored the relationship between signal degradation and electrophysiological measures of speech processing, in order to understand how these measures relate to intelligibility and listening effort. Subjects heard two talkers presented to different ears, with the target talker presented in quiet, three levels of speech-shaped noise ( + 3 dB, -0.5dB, -4dB SNR), or a 14-channel noise vocoder. The speech materials were simultaneous sentences that varied in final-word predictability; subjects were asked to monitor the sentences for catch trials (i.e., semantically anomalous final words). The results demonstrated that cortical entrainment to the amplitude envelope of the target was higher than for the distractor, as found in previous studies. Entrainment and lexical processing are robust with increasing noise, then fall when the stimulus becomes very poorly intelligible. Unexpectedly, results from the vocoded condition indicate no entrainment advantage for the target speaker, even when this condition is intelligible.
Detection of lymph node metastasis using photoacoustic imaging and glycol-chitosan-coated gold nanoparticles
Authors: Dumani Diego , Sun In-Cheol , Emelianov Stanislav
Published: April 2018

Metastases, rather than primary tumors, are responsible for majority of deaths in cancer patients. We developed a non-invasive method to detect sentinel lymph node (SLN) metastasis using combined ultrasound and photoacoustic (US/PA) imaging with glycol-chitosan-coated gold nanoparticles (GC-AuNP). The spatio-temporal distribution of GC-AuNP is affected by presence of metastasis, which is detected by US/PA. GC-AuNPs (100 μl, 0.1 mg Au/ml) were injected peritumorally in breast tumor-bearing mice, and allowed to drain for 24 hours into the SLN. The SLN was located using b-mode ultrasound, and multi-wavelength PA was used to detect GC-AuNPs. Spectroscopic analysis allowed to isolate the signal from GC-AuNPs and quantify their accumulation in the SLN after cellular uptake and transport by immune cells. Results show that distribution of GC-AuNPs in the SLN was affected by presence of metastasis. The overall accumulation was also reduced, with more than 20% signal decrease compared to non-metastatic controls. Histological analysis confirmed that distribution of GC-AuNP-containing immune cells is reduced due to presence of metastatic cells. Our method successfully distinguishes metastatic from non-metastatic lymph nodes using biocompatible nanoparticles and could aid physicians in detection of micrometastasis thus guiding and avoiding unnecessary SLN biopsy.
Impact of the interaural stimulation timing mismatch on localization performance in bimodal HA/CI users
Authors: Zirn Stefan , Angermeier Julian M. , Wesarg Thomas
Published: April 2018

The normal-hearing human auditory system is able to perceive interaural time differences (ITD) as small as 10 μs. The largest ITD occurring physiologically is about 700 μs. In bimodal users differences in processing latencies of digital hearing aids (HA) and cochlear implants (CI) up to 9 ms superpose these tiny ITD resulting in an interaural stimulation timing mismatch. Our hypothesis in the present study is that this interaural stimulation timing mismatch impairs sound localization in bimodal HA/CI users. To investigate, we conducted localization tests in bimodal users with and without differences in processing latencies. To compensate for individual processing latency differences we designed a wearable programmable delay line based on a circular buffer implemented on a microcontroller in order to delay the faster device (the CI system). In each subject, an initial localization test with the delay line deactivated was conducted. Afterwards the delay line was activated followed by a 1 hour familiarization period. Finally, the localization test was repeated. Results showed an improvement in sound localization in the horizontal plane of 10 % averaged across 8 bimodal users after compensation. The effect was significant (p<.05) using a Wilcoxon signed rank test.
Assessing perceived listening difficulty using behavioral gaze patterns for audiovisual speech
Authors: Sheffield Sterling W. , Bernstein Joshua G.
Published: April 2018

Listeners alternate their gaze between the talker’s eyes, nose, and mouth during conversation, spending more time gazing directly at the mouth in more difficult listening conditions. Perceived listening difficulty and speech perception performance vary independently, demonstrated with indirect measures of perceived listening difficulty/effort such as pupil dilation and dual task paradigms. This study took a more direct approach, evaluating whether perceived listening difficulty could be assessed by observing a listener’s natural gaze pattern in a challenging speech-perception task. The proportion of time spent gazing at the talker’s mouth was measured for auditory-visual speech perception in conditions that produced equal percentage-correct scores, but where one condition was designed to produce greater perceived difficulty. Experiment 1 compared gaze proportion for a speech-shaped noise versus two same-gender interfering talkers. Experiment 2 examined the effect of sentence context using low and high-probability sentences. The results are discussed in terms of the potential application of the eye-gaze metric to evaluate rehabilitative interventions in cases where subjectively reported benefits do not manifest in improved speech-understanding scores. [The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. Government.]
Nonlinear properties of an electrically coupled acoustic metamaterial
Authors: Smoker Jason J. , Titovich Alexey S.
Published: April 2018

Efforts in the field of acoustic metamaterials have often remained in the material design and property identification domain due to difficulty in realizing physical manifestations of necessary material properties. This is especially true in the domain of transformation acoustics. In a number of classical approaches, research has relied on physical dynamics in the linear region to design an effective density or bulk modulus. Such work has limited achievable designs. This work aims to demonstrate the use of electrically coupled non-linear dynamics to increase the design space of acoustic metamaterials. Numerical models are leveraged for analysis and utilized to demonstrate efficiencies in real world configurations.
Optimal absorption associated with wall impedance in acoustic waveguides
Authors: Kelsten Matthew , Norris Andrew
Published: April 2018

In a previous talk at ASA it was shown that the double root for modal frequencies in a 2D waveguide can exhibit almost perfect absorption over a relative broad frequency range. The key to the phenomenon is that the wall impedance is such that modes coalesce at a complex-valued frequency. In this talk we consider the more realistic case of circularly symmetric waveguides. Numerical simulations are shown for reflection and transmission from a waveguide with impedance boundary conditions associated with double roots. The results again show large and almost perfect absorption at frequencies near the real part of the complex root. The model is linked to realistic passive impedance values based on various models for boundary impedance, including perforated and porous panels. These comparisons are discussed to illustrate the feasibility of optimized wall impedances in absorbing sound passing through ducts. Preliminary experimental data will be presented. Work supported by NSF.
Acoustic gradient index lens design using gradient based optimization
Authors: Amirkulova Feruza , Caton Samuel T. , Schrader Morgan , Gobel Trenton J. , Norris Andrew
Published: April 2018

We demonstrate a gradient based optimization of the absolute acoustic pressure at a focal point by incrementally repositioning a set of cylindrical obstacles so that they eventually act as an effective gradient index (GRIN) lens. The gradient-based optimization algorithm maximizes the absolute pressure at the focal point by analytically evaluating its derivative with respect to the cylinder positions and then perturbatively optimizing the position of each cylinder in the GRIN lens device while taking into account acoustic multiple scattering between the cylinders. The method is presented by examples of sets of hard cylinders and sets of elastic cylindrical shells of uniform size. Designs using available cylindrical shells enable easy and realistic fabrication of acoustic GRIN lenses. Computations are performed on MATLAB using parallel optimization algorithms and a multistart optimization solver, and supplying the gradients of absolute pressure at the focal point with respect to position vectors. Providing the analytic form of the gradients enhances modeling by allowing the use of exact gradients with optimization algorithms and parallel computing. This results in reducing number of function calls and time needed to converge, and improving solution accuracy for large scale optimization problems especially at high frequencies and with a large number of scatterers.
Generalization in foreign accent adaptation is predicted by similarity of segmental errors across talkers
Authors: Hosier Jordan , Pajak Bozena , Bradlow Ann , Bicknell Klinton
Published: April 2018

Comprehension of foreign-accented speech improves with exposure. Previous work demonstrates that listeners who adapt to accented talkers generalize that adaptation to other accented talkers—exposure to multiple talkers of the same accent facilitates comprehension of a novel talker of that accent (e.g. Bradlow and Bent, 2008) and exposure to multiple novel accents facilitates comprehension of yet another novel accent (Baese-Berk et al., 2013). To examine possible theories of accent adaptation and generalization, we created a new dataset of phonetically transcribed accented speech produced by the training and test talkers used as stimuli in studies of accented speech generalization (Bradlow and Bent, 2008; Baese-Berk et al., 2013). Using this dataset, we computed the (cosine) similarities between accented talkers in a multidimensional accent space defined by the rates at which talkers made different segment-level phonetic errors. Results show that similarity in this space accounts for all significant differences between training conditions in Bradlow and Bent (2008) and Baese-Berk et al. (2013): training conditions including more of the same types of phonetic errors as those of the test talkers led to better test talker comprehension. These results suggest that prior accent generalization results are compatible with simple, segment-error driven theories of adaptation.
Speech learning in noise or quiet
Authors: Mi Lin , Tao Sha , Wang Wenjing , Dong Qi , Liu Chang
Published: April 2018

Noise made speech perception much more challenging for non-native listeners than for native listeners. We proposed that speech training in noise may better improve non-native listeners’speech perception. In the present study, three groups of native Chinese listeners were trained on English vowel perception under three conditions including quiet (TIQ), noise (TIN), and watching videos in English as an active control (C). Vowel identification in quiet and noise was assessed before, right after training, and three months later after training. Results showed that all listeners significantly improved their vowel identification after training, and the training effect was retained three months later. Compared with the control group, the TIQ group improved more for vowel identification in quiet condition, but not for that in noise conditions. The TIN group improved vowel identification in noise significantly more than the TIQ and control groups. Compared with the TIQ，less informational masking and energetic masking was also found in the post-training test for the TIN than that for the TIQ. These results suggested that vowel perceptual training in noise may better improve L2 vowel perception in adverse acoustic environments than training in quiet. Implications for second language speech perception training were discussed.
Voice onset time and onset f0 as correlates of voicing in American learners of French
Authors: Hutchinson Amy , Dmitrieva Olga
Published: April 2018

Voice Onset Time (VOT) and onset f0 are known correlates of voicing distinctions in stops and both contribute to the perception of voicing (House & Fairbanks, 1953; Abramson & Lisker, 1965). The values of VOT and onset f0 which correspond to voicing categories vary cross-linguistically. Second language (L2) learners often have to acquire a novel use of these acoustic cues to produce and perceive L2 voicing. The acquisition of primary voicing cue, VOT, has been studied extensively in L2 research (Flege & Eefting, 1988; Flege 1991; Birdsong et al. 2007) but less is known about the acquisition of secondary cues. The present study compares the use of VOT and onset f0 in French and English speech produced by American learners of French (22). The study also examines the role of back transfer in L2 learners by comparing their English productions to a monolingual control group (33). The results demonstrate that although learners’ VOT values in French were heavily influenced by English, their onset f0 production in both English and French was on target. Little evidence of learners’ second language affecting their first language was found. Individual trends, including the effect of L2 proficiency level will also be explored.
First language phonetic drift in second language instructional environment
Authors: Dmitrieva Olga , Tews Alexis N.
Published: April 2018

Recent research demonstrates that second language learning can affect first language speech production. This has been shown for proficient long-term second language learners in immigration settings (Flege, 1987) as well as novice learners in the study abroad setting (Chang, 2013). The question addressed in the present study is whether learners acquiring a second language in a classroom setting in the first language-dominant environment are also subject to L1 phonetic drift. A group of American students enrolled in intermediate-level Russian language courses at a major Mid-Western university were recorded reading a list of Russian and English words designed to investigate the acoustic realization if word-initial and word-final stop voicing. Several acoustic correlates of initial and final voicing were measured (VOT, onset f0, preceding vowel duration, glottal pulsing, etc.) and compared to data from monolingual speakers of American English from the same geographic region. Results demonstrate that learners’ realization of both initial and final voicing in English are affected by exposure to Russian. In the majority of measures, the drift occurred in the direction of norms characteristic of Russian voicing. Divergence from Russian was detected in the use of negative VOT for initial voiced stops.
Effect of L1 phonation contrast on production of L2 English stops
Authors: Schertz Jessamyn L.
Published: April 2018

This work examines the influence of native phonation contrast type on the production of English stops in different phonetic contexts/reading styles. Proficient English speakers from four different L1 language backgrounds produced words in three different contexts: words in isolation, phrase-final in a carrier sentence, and in a reading passage. Language backgrounds were representative of three types of phonation contrasts: Mandarin (aspiration contrast: [pʰ ~ p]), Tagalog (voicing contrast: [p ~ b]), and Urdu (4-way phonation contrast [pʰ ~ p ~ bʰ ~ b]). 11 participants from each group were compared with a control group of L1 English speakers. Aspiration and closure voicing were measured. All groups produced English voiceless stops as aspirated; however, there was considerable variation in the voiced stops, with Mandarin speakers producing less voicing, and Urdu and Tagalog speakers producing more voicing, than English speakers across speech styles, showing an asymmetrical influence of L1 phonation on production of the English contrast, in line with other recent work.
Second-language learning in adolescents with cochlear implants
Authors: Baskent Deniz , Jung Dorit Enja , Lowie Wander , Sarampalis Anastasios
Published: April 2018

Speech signals delivered via cochlear implants (CIs) lack spectro-temporal details, yet, young-implanted children can develop good native language skills (L1). This study explores three research questions: 1. Can adolescents with CIs learn a second language (L2)? 2. Is there a difference in spoken (auditory-A) vs. written (visual-V) L2 skills? 3. Which perceptual and cognitive factors influence L2 learning? Two groups (L1 = Dutch, age 12—17 years), one with normal hearing (NH) and one with CIs, and both learning English (L2) at school, participated. L1 and L2 proficiency was measured in receptive vocabulary (A), comprehension (A, V), and general proficiency (V). Further, basic auditory functioning, in temporal (gap detection) and spectral (spectral ripple detection) resolution, and cognitive functioning, in IQ, working memory, and attention, were measured. Preliminary data (n = 7 per group) indicated comparable L1 proficiency between NH and CI groups. While some CI users showed L2 proficiency within the NH range, on average, L2 proficiency was lower for the CI group. This effect was more pronounced for auditory tests. Reduced temporal and spectral resolution, but no difference in cognitive tests, were observed in CI group compared to NH, emphasizing the importance of auditory factors in L2 learning.
Production and perception of phonetically “non-native” clusters by Georgian native speakers
Authors: Kwon Harim , Chitoran Ioana
Published: April 2018

This study examines the role of native inter-consonant timing patterns in perception and production of word-initial consonant clusters, asking how phonotactically native clusters with non-native timing patterns are perceived and produced by speakers of a cluster-heavy language. We tested Georgian speakers in two experiments using CCV/CVCV stimuli produced by a French talker. Georgian is a cluster-heavy language with a relatively long inter-consonant lag, often resulting in transitional vowels between two consonants within a cluster. French onset clusters have shorter inter-consonant lag than Georgian ones. In Experiment 1 (shadowing), Georgian participants (n = 14) were exposed to French CCV/CVCV stimuli and asked to produce what they heard. In Experiment 2 (discrimination), the same Georgian participants heard the same French stimuli in AX pairs and determined whether the two sequences (A and X) were the same or different. The results from the two experiments suggest that Georgian participants often confused French CCV (without any vocalic transition) with French CVCV. The confusion occurred almost exclusively when the first vowel of CVCV was /ø/, which is acoustically similar to the transitional vowel in Georgian, but did not seem to stem from Georgian speakers' incapability of producing French short-lag CCV. We claim that native inter-consonant timing patterns influence perception and production of consonant clusters even when the clusters are phonotactically licit in one’s native language.
Perceiving allophonic alternations in an immersion setting: The case of alveolars and rhotics in Spanish and English
Authors: Neumann Farrah A.
Published: April 2018

Recent research indicates that second language (L2) immersion influences the phonetic production not only of the L2 (Jacobs, Fricke, & Kroll, 2016), but also of the first language (L1) (Chang, 2012). However, less understood is the immediate impact of L2 immersion on cross-language influence in phonetic perception. This study tracked L2 Spanish study abroad learners’ perceptual shifts due to immersion using auditory-visual cross-modal priming experiments in both Spanish and English. The target phones, [r, ɾ, t, d, ð, ɹ], were chosen for their differing phonemic and allophonic statuses in Spanish and English. For example, Spanish rhotics include the phonemic trilled /r/ and tapped /ɾ/, whereas the tapped /ɾ/ exists phonetically in English, but as an allophone of the alveolar stops /t d/. Because learners must adjust their phonological inventories to accommodate the L2 statuses of these phones, we expect their L1 inventories to also reflect these changes, as evidenced by slower RTs for the prime-target pairs that do not correspond to the L2. This study provides a fuller perspective on how immersion mediates L1-L2 interference, and offers insight as to whether perceptual changes in the two languages are necessarily related. Data analyses are currently underway.
Cross-correlation method for acoustic detection of small unmanned aerial vehicles
Authors: Sedunov Alexander , Salloum Hady , Sutin Alexander , Sedunov Nikolay
Published: April 2018

The availability of Unmanned Aerial System (UAS) to consumers has increased in the recent years, with it came the potential for negligent or nefarious misuse of them. Stevens Institute of Technology has built a passive acoustic system for low flying aircraft detection, the application of the developed principles and algorithms for UAS acoustic detection and tracking is presented in this paper. The application of the developed principles and algorithms for UAS acoustic detection and tracking is presented in this paper. Several experiments were conducted aiming to establish the characteristics of the emitted noise of UAVs of various sizes while airborne and demonstrate the processing required to detect and find the direction toward the source. The vehicles tested included popular quadrotors: DJI Phantom 2 Vision + , 3DR Solo, DJI Inspire 1 as well as larger semi-professional vehicles: Freefly Alta 6, DJI S1000. The small array of 16 microphones was used for data collection in the tests near local NJ airport. Acoustic signatures of the tested UAS were collected for stationary and flying UAS. We applied the algorithm for detection and direction finding based on fusing time difference of arrival (TDOA) estimates computed by finding peaks in the output Generalized Cross-Correlation (GCC) function. The cross-correlation signal process provided UAS detection and bearing for distances up to 250m while the spectrograms did not reveal acoustic UAS signatures at that distance. This work is being supported by DHS’s S&T Directorate.
Stereo I/O framework for audio signal processing on android platforms
Authors: Küçük Abdullah , Hao Yiya , Ganguly Anshuman , Panahi Issa M.
Published: April 2018

Smartphones and tablets are attractive cost-effective solutions for implementing multi-channel audio signal processing algorithms. Modern smartphones and tablets have at least two microphones and requisite processing capabilities to perform real-time audio signal processing. However, it is still challenging to integrate the dual-microphone audio capture and the audio processing pipeline in real-time for efficient operation. In this paper, we propose an efficient stereo input/output framework for real-time audio signal processing on Android smartphones/tablets. This framework enables us to perform a large variety of real-time signal-processing applications on Android platform such as Direction of Arrival (DOA) estimation, Audio Compression, and Multi-Channel Speech Enhancement. The implementations and demos of Direction of Arrival (DOA), Audio Compression, and Multi-Channel Speech Enhancement algorithms are also presented to show the effectiveness of proposed framework.
Time delay estimation via zero-crossing of envelope
Authors: Jung Donghwan , kim Jea Soo
Published: April 2018

Time-delay estimation of an acoustic signal in an ocean waveguide is a challenging due to the received signal corrupted by noise and phase distortion caused commonly by reflection of the transmitted signal traveling to a remote receiver via more than one path. In this study, envelope-based Hilbert transform method is applied to enhance the accuracy of time-delay estimation. Through the mathematical interpretation and numerical simulations, the proposed method is compared to the conventional time-delay estimation methods (e.g., cross correlation and zero-crossing of Hilbert transform). It is found that the envelope-based Hilbert transform method more efficiently estimates the time-delay than the conventional methods and resolve ambiguity of time delay estimate.
Methods of suppressing tow ship noise with a horizontal linear array
Authors: Feng Jia , Zou Nan , Wang Yan , Hao Yu
Published: April 2018

Tow ship noise seriously influence the detection and direction of arrival (DOA) estimation performance of towed array. Null steering beamforming(NSBF), inverse beamforming(IBF) and non-data based beam-space transformation(NDBBT) are applied to suppress interference of tow ship in this paper. These methods are evaluated according to the improvement of signal interference noise ratio and DOA estimation precision. Simulation and experimental results show that all three methods can suppress interference of tow ship effectively so as to improve DOA estimation precision. In addition, IBF and NDBBT do better in suppressing interference than NSBF.
A robust smartphone based multi-channel dynamic-range audio compressor for hearing aids
Authors: Hao Yiya , Zou Ziyan , Panahi Issa M.
Published: April 2018

Hearing impairment degrades perception of speech and audio signals due to low frequency-dependent audible threshold levels. Hearing aid devices (HADs) apply prescription gains and dynamic-range compressor for improving users’ audibility without increasing the sound loudness to uncomfortable levels. Multi-channel dynamic-range compressor enhances quality and intelligibility of audio output by targeting each frequency band with different compression parameters such as compression ratio (CR), attack time (AT), and release time (RT). Increasing the number of compressor channels can result in more comfortable audio output when appropriate parameters are defined for each channel. However, the use of more channels increases computational complexity of the multi-channel compressor algorithm limiting its application to some HADs. In this paper, we propose a nine-channel dynamic-range compressor with an optimized structure capable of running on smartphones and other portable digital platforms in real time. Test results showing the performance of proposed method are presented too.
Neural mechanisms of selective listening to pitch and timbre in musical sounds
Authors: Zhang Yang , Grice-Patil Zach , Burton Phillip , Olman Cheryl
Published: April 2018

Previous research showed that different dimensions of sound such as pitch and timbre elicit distinct patterns of neural activities. Here, we report event related potential (ERP) along with functional magnetic resonance imaging (fMRI) data during a selective listening task of musical sounds. The participants were 12 normal adults. The stimuli were 4 musical tones with timbre (piano vs. violin) and pitch (high vs. low) contrasts. The stimuli were normalized for duration and intensity. In the timbre condition, the listener needed to indicate the instrument category. In the pitch condition, the listener needed to indicate the pitch level. While both conditions reached the ceiling-level accuracy, the pitch condition required significantly longer reaction time. Significant fMRI activations were found in the superior temporal gyri with right dominance for both conditions. The right superior temporal gyrus and left inferior frontal regions were important for coding pitch whereas the anterior cingulate cortex was exclusively active in selectively attending to timbre. These data demonstrate how different cortical networks contribute to selective listening. The ERP data further showed larger N1 and N2 peaks for the timbre condition than the pitch condition, suggesting that attentional modulation operates at both early and later stages of processing for selective listening.
Effect of musical training on EEG measures of spectro-temporal processing
Authors: Dirks Coral , Shahin Anthony , Kwan Timothy , Davies-Venn Evelyn E.
Published: April 2018

Recent studies show that musical training enhances auditory processing abilities such as sensitivity to temporal fine structure and narrowband frequency resolution. Little is known about the effect of musical training on broadband spectro-temporal processing using rippled noise. This study evaluated whether musician enhancement in frequency resolution can be generalized to broadband spectro-temporal resolution using electrophysiological measures. We tested the hypothesis that musicians have enhanced broadband spectral resolution abilities compared to non-musicians. Spectral processing was measured using P1 N1 P2 responses to spectro-temporally modulated rippled noise. The test stimulus was spectro-temporally modulation wideband (4 octaves) rippled noise from 350 to 5600 Hz. EEG recordings were made using a 32-channel standard 10/20 configuration BioSemi system with a sampling rate of 4 kHz. For each condition, 1000 repetitions of the test stimuli were presented at 100% modulation with 2 Hz temporal modulation via electrically shielded ER-3A earphones, using a passive listening paradigm. The amplitude and latency of the P1-N1-P2 components were measured to determine whether musicians had better sensitivity to spectro-temporal modulation compared to age-matched non-musicians. Results to date show slight musician enhancement in spectral processing. The clinical implications of these findings for auditory-rehabilitation will be discussed.
Impact of phonatory frequency and intensity on glottal area waveform measurements derived from high-speed videoendoscopy
Authors: Patel Rita R. , Döllinger Michael , Kniesburges Stefan
Published: April 2018

Measurements of glottal area waveform from high-speed videoendoscopy were made on vocally healthy females (n = 41) and males (n = 25) during sustained /i/ production at typical pitch and loudness, high pitch, and soft phonation. Three trials of each condition were performed yielding 594 samples. Statistical analysis of glottal cycle quotients (open quotient (OQ), speed quotient (SQ), rate quotient (RQ), glottal gap index (GGI)), glottal cycle periodicity (amplitude, time (TP)), glottal cycle symmetry (phase asymmetry index, spatial symmetry index, and amplitude symmetry index), glottal area derivative (maximum area declination rate (MADR)), and mechanical stress measures (stiffness index (SI), amplitude-to-length ratio (ALR)) revealed that only SI varied systematically across pitch and loudness conditions for males and females. Variations in pitch and loudness results in changes in SI, ALR, RQ, MADR, and SQ for females, whereas variations in target pitch and loudness results in changes in SI, ALR, RQ, MADR, GGI, OQ, and TP for male speakers. Carefully selecting the laryngeal parameters derived from high-speed videoendoscopy has the potential to provide insights clinically into the known laryngeal biomechanics expected for the increase in pitch and reduction in vocal loudness.
Voice instabilities in a three-dimensional continuum model of phonation
Authors: Zhang Zhaoyan
Published: April 2018

The goal of this study is to identify vocal fold conditions that produce irregular vocal fold vibration and the underlying physical mechanisms. Using a three-dimensional computational model of phonation, parametric simulations are performed with co-variations in vocal fold geometry, stiffness, and vocal tract shape. For each simulation, the cycle-to-cycle variations in the amplitude and period of the glottal area function are calculated, based on which the voice are classified into three types corresponding to regular, quasi-steady or subharmomic, and chaotic phonation. The results show that the presence of a vocal tract significantly increases the occurrence of irregular vocal fold vibration, which naturally occurs even under symmetric vocal fold conditions, in particular for vocal folds with very low transverse stiffness in the coronal plane or a soft vocal fold body layer. The occurrence of voice instability is suppressed by increasing the transverse stiffness, increasing the body-cover ratio in the longitudinal stiffness, or decreasing the subglottal pressure. The implications of these observations on the production of certain voice qualities are discussed. [Work supported by NIH.]
Palate shape and articulatory range
Authors: Johnson Keith
Published: April 2018

Using the Wisconsin X-ray microbeam corpus, this paper explores the relationship between palate shape in the saggital plane and articulatory variation. The corpus has been updated with tags (Praat Textgrids) marking the acoustic onsets and offsets of words and phones. In addition, the sound files have been translated to WAV format, and the articulatory data saved as plain text files. The shape of the palate for each of 57 speakers of American English was measured in terms of the total 2D area of the palate vault above the occlusal plane. Articulatory variability was measured in terms of the interquartile ranges of the x and y locations of 7 pellets attached to the tongue (4 pellets), lips (upper and lower), and jaw. Although there is a significant correlation between palate area and the range of motion of some articulators (particularly on the body of the tongue, but surprisingly to this author, not the motion of the jaw), the study also finds that there is a great deal of variation among speakers. Articulatory motions involved in particular speech sounds will also be examined to determine if there are specific patterns of variation associated with the palate size.
Timing patterns of voiceless and voiced singleton and geminate plosives of Yanagawa Japanese
Authors: Shinohara Shigeko , Hussain Qandeel , Fujimoto Masako
Published: April 2018

The paper examines acoustic timing patterns of word-medial voiceless and voiced singleton and geminate plosives of Yanagawa Japanese, one of the Chikugo varieties of Japanese spoken in the center of Kyushu (Japan). Unlike standard Tokyo Japanese, Yanagawa Japanese is characterized by frequent gemination of any types of consonants including voiced obstruents (e.g., /kuzzoko/ [kuddzoko] “sole, the fish,” /miroɡɡe/ [miɾoɡɡe] “a shell fish”). Five Yanagawa Japanese speakers were recorded. Another five speakers of standard Tokyo Japanese were also recorded as a control group. The stimuli consisted of nonsense words with C1V1C(C)2V2 structure (e.g., /kak(k)a/, /kaɡ(ɡ)a/). The findings suggest that the whole word duration containing geminate consonants was longer in proportion to mora count difference those containing singleton consonants, confirming moraic timing at word level in Yanagawa Japanese. When C2 was a geminate (voiceless or voiced), it lengthened the preceding vowel (V1) and shortened the following one (V2) in both dialects. However, the magnitude of influence of geminates to adjacent vowels was dialect specific: V1 duration in Yanagawa was consistently longer than Tokyo when the following consonant was a geminate. The results of the current study point towards the timing differences in singletons and geminates across Japanese dialects.
Phonetic realization of vowel reduction in Brazilian Portuguese
Authors: Oh Sejin
Published: April 2018

This study explored the phonetic realization of vowel reduction in Brazilian Portuguese, which reportedly exhibits raising of non-high vowels in unstressed syllables. Specifically, we tested the influence of speech rate on the realization of /a/ in five prosodic positions: word-initial pretonic, medial pretonic, tonic, medial posttonic, and final posttonic. The results showed that, while both speech rate and prosodic position had a clear effect on the phonetic duration of vowels, F1 values were far better predicted by the vowel’s prosodic position (non-posttonic vs. posttonic), although some effects of speech on F1 were observed in vowels at word edges. Correlations between phonetic duration and F1 were statistically significant but generally weak in all positions. We argue these findings suggest that vowel reduction in Brazilian Portuguese primarily reflects phonological patterning rather than phonetic undershoot, although phonetic reduction is also apparent. We discuss the results in the context of cross-linguistic studies of vowel reduction, and the relation between phonetics and phonology.
Place of articulation effects on voice onset time and phonation bleed persist in languages with no voicing distinction
Authors: Kakadelis Stephanie , Whalen D. H.
Published: April 2018

Place of articulation effects on voice onset time (VOT) and phonation bleed in the closure of oral stops has been observed in languages which utilize these as perceptual correlates to voicing distinctions (Lisker & Abramson, 1967; Ohala & Riordan, 1979). In this study, measurements from intervocalic oral stops were collected from three No Voicing Distinction (NVD) languages, Bardi (ISO-639 bcj), Arapaho (ISO-639 arp), and North Puebla Nahuatl (ISO-639 ncj). Tokens surfacing with positive VOT increased in duration as place of articulation went from more anterior to dorsal. VOT for Arapaho coronal oral stops was longer on average than velar orals stops. Nahuatl showed a similar pattern, with average VOT increasing from labial to coronal to velar. Average VOT for Arapaho labial tokens and all Bardi tokens was negative, so they were not included in VOT measurements. Conversely, average duration of phonation bleed in all three languages was greatest for labial oral stops, decreasing in average duration for coronals and velars. This suggests a physiological effect of vocal tract volume on both VOT and maintenance of phonation during the closure of an oral stop even in the absence of a phonological distinction.
Shifting from the shift: Loss of dialect distinction in the US
Authors: Nesbitt Monica
Published: April 2018

Historically, /æ/ in the Northern Cities Shift (NCS) dialect area is realized as raised, lengthened, and diphthongized in all consonantal contexts (Boberg and Strassel 2000) and that pre-oral /æ/ is realized with as much nasalization as pre-nasal /æ/ (Plichta 2004). Recent studies suggest that young speakers in the dialect area are adopting a nasal pattern for /æ/ such that only tokens before nasal consonants are raised and fronted in phonetic space (in Lansing, MI (Wagner et al. 2016), in Syracuse, NY (Driscoll and Lape 2015), in Upstate NY (Thiel and Dinkin 2017), in Detroit, MI (Acton et al. 2017)). Through acoustic analysis of 1310 /æ/ tokens produced by 26 speakers born and raised in Lansing, MI (date of birth 1991–1997), the current study finds that younger speakers are not simply lowering and retracting this vowel, they are rejecting all phonetic components of the NCS /æ/ system. For these speakers, only pre-nasal /æ/ tokens are realized as long, diphthongal, and nasalized, while pre-oral tokens are short, monophthongal, and have little to no nasalization. Vowel quality for /æ/ in the NCS dialect area is thus undistinguishable from that in the western and midland states in the US (e.g., California and Kansas).
A sociophonetic analysis of gay male speech stereotypes in Buenos Aires, Argentina
Authors: Davenport Ellis
Published: April 2018

The present study expands academic knowledge on the phonetic cues that index “gay speech” beyond the English language by examining speech produced by gay Buenos Aires Spanish (porteño) speakers. Research has been conducted on gay speech in other parts of Latin America or on the Spanish language in general (Pahis 2017, Ezquerra 2015, Mack 2011, Mendes 2007, Sívori 2005), but not on the porteño dialect. Acoustic features (vowel quality, pitch, speech rate, and degree of aspiration of pre-consonantal and syllable-final /s/) corresponding to public stereotypes on porteño gay speech were measured. Speech from gay and straight men, as well as actors interpreting gay & straight roles in film and television, was analyzed. It is hypothesized that gay men will have higher pitch and that vowels be more clearly articulated than straight counterparts, that pre-consonantal and syllable-final /s/ will be aspirated less frequently and that pitch contours will be more pronounced in the speech of gay men. In addition, the speech of actors playing gay roles will align more closely with the stereotypes of gay speech than with actual phonetic properties, in accordance with Cartei and Reby 2011.