bluuebunny/crossref_metadata_2025 huggingface dataset:
Target response in a focused, modulated sound field: Modeling and experiment
Authors: Daniel Timothy D. , Marston Philip L. , Abawi Ahmad T. , Kirsteins Ivars P.
Published: April 2018

In a previous work, we had shown that low frequency flexural modes of circular plates and cylinders could be excited using modulated radiation pressure generated by focused ultrasound [ J. Acoust. Soc. Am. 139, 2053 (2016)]. We recently conducted experiments probing how the response of these targets varied as a function of position in the focused ultrasound field. Surprisingly, the response of the circular plate was found to change sign as it was moved away from the source. Two different models were developed to analyze the target response and understand this sign change. A purely geometric model based on ray optics and a semi-physical optics model that uses the incident intensity calculated for the focused source, using a Rayleigh-Sommerfeld integral. Both geometric and semi-physical optics models predict a sign change for the plate response at approximately the correct distance from the source. The sign change is due to a factor in a mode projection that more strongly weights points farther from the center of the plate. The physical optics model was also applied to cylindrical targets. [Work supported by ONR.]
Potential of theoretical approach and T-matrix method for designing numerical acoustical tweezers toolbox
Authors: Gong Zhixiong , Marston Philip L. , Li Wei
Published: April 2018

Partial-wave series solution and T-matrix method (TMM) could be used for computations of radiation force and torque exerted on objects from an acoustic Bessel beam (ABB) with arbitrary order and location. The radiation force and torque in Bessel beams could be expressed in terms of incident and scattered coefficients which could be obtained analytically based on the multipole expansion method [Gong et al., J. Acoust. Soc. Am. 141, EL574–578 (2017)].The investigation of radiation force and torque could be used to design numerical acoustical tweezers toolbox that may manipulate particles and cells as expected, showing potential in physical chemistry, biomedicine, and so on. This work claims the possibility and potential of the theoretical and numerical methods for acoustical tweezers toolbox which could trap, pull, push, and rotate targets of different shapes and components. Both the progressive and (quasi)standing Bessel beams will be considered. In addition, beams which could be expanded in terms of basis functions, for example, Gaussian beams, could also be included in this numerical toolbox. The numerical toolbox of acoustical tweezers could help to guide experimental set-ups. [Work supported by NSFC (W.L. and Z.G.), ONR (P.L.M.), and China Scholarship Council (Z.G.).]
Research on hearing-aid self-adjustment by adults
Authors: Mackersie Carol , Boothroyd Arthur , Garudadri Harinath
Published: April 2018

The purpose of the work is to develop a protocol for user self-adjustment of hearing aids and to determine its efficacy and candidacy. An initial study involved 26 adults with hearing loss. Control of overall volume, high-frequency boost, and low-frequency cut employed prerecorded and preprocessed sentence stimuli. Participants took a speech-perception test after an initial self-adjustment and then had the opportunity to repeat the adjustment. The final self-selected outputs were not significantly different from those prescribed by a widely used threshold-based method (NAL-NL2)—regardless of prior hearing-aid experience. All but one participant attained a speech-intelligibility index of 60%. Previous users of hearing aids, however, did not meet this criterion until after taking the speech-perception test. This work is continuing with the UCSD Open-source Speech-processing Platform which provides real-time, six-band, processing of microphone input from ear-level transducer assemblies. This system provides a more realistic participant experience, finer control of level and spectrum, and places no limits on the speech materials used for self-adjustment and outcome assessment. Ongoing work investigates the need for the speech-perception test as part of the self-adjustment protocol and the importance of the level and spectrum from which users make their initial adjustments.
Robust and real-time decoding of selective auditory attention from M/EEG: A state-space modeling approach
Authors: Miran Sina , Akram Sahar , Sheikhattar Alireza , Simon Jonathan Z. , Zhang Tao , Babadi Behtash
Published: April 2018

Humans are able to identify and track a target speaker amid a cacophony of acoustic interference, which is often referred to as the cocktail party phenomenon. Results from several decades of studying this phenomenon have culminated in recent years in various promising attempts to decode the attentional state of a listener in a competing-speaker environment from M/EEG recordings. Most existing approaches operate in an offline fashion and require the entire data duration and multiple trials to provide robust results. Therefore, they cannot be used in emerging applications such as smart hearing aids, where a single trial must be used in real-time to decode the attentional state. In this work, we close this gap by integrating various techniques from state-space modeling paradigm such as adaptive filtering, sparse estimation, and Expectation-Maximization, and devise a framework for robust and real-time decoding of the attentional state from M/EEG recordings. We validate the performance of this framework using comprehensive simulations as well as application to experimentally acquired M/EEG data. Our results reveal that the proposed real-time algorithms perform nearly as accurate as the existing state-of-the-art offline techniques, while providing a significant degree of adaptivity, statistical robustness, and computational savings.
Realistic virtual audiovisual environments for evaluating hearing aids with measures related to movement behavior
Authors: Hendrikse Maartje M. , Llorach Gerard , Grimm Giso , Hohmann Volker
Published: April 2018

With increased complexity of hearing device algorithms a strong interaction between motion behavior of the user and hearing device benefit is likely to be found. To be able to assess this interaction experimentally more realistic evaluation methods are required that mark a transition from conventional (audio-only) lab experiments to the field. In this presentation, we describe our methodology for acquiring ecologically valid behavioral data in realistic virtual audiovisual testing environments. The methods are based on tools to present interactive audiovisual environments while recording subject behavior with gaze and motion tracking systems. The results of a study that evaluated the effect of different types of visual information (e.g., video recordings vs. animated characters) on behavior and subjective user experience are presented. It was found that visual information can have a significant influence on behavior and that it is possible to systematically assess this. Furthermore, first results are presented of two studies that observed head and eye movement behavior: (1) in typical everyday listening situations that were replicated with virtual audiovisual environments in the lab (e.g., cafeteria) and (2) when visual cues were presented via a head-mounted display or projected onto a panoramic cylindrical screen in front of the subject.
Neural coding of perceptual temporal asymmetry for sounds with rising vs. falling intensity envelopes in non-attentive and attentive listening conditions
Authors: Cheng Bing , Zhang Yang , Tanaka Keita , Schlauch Robert S. , Imada Toshiaki
Published: April 2018

Behavioral studies have shown that ramped sounds are judged to be louder and longer than damped sounds. Here we employed magnetoencephalography (MEG) to examine cortical processing of the perceptual temporal asymmetry. The participants were 6 normal-hearing right-handed male adults. The synthesized stimuli included three kinds, pure tone, piano note, and broadband noise with time-reversed intensity envelopes for the ramped vs. damped comparison. Each stimulus was 200 ms. In the non-attentive condition, subjects were instructed to watch a silent movie and ignore the randomly presented tones. In the attentive condition, listeners were required to judge whether the first or the second of paired sounds was longer. The stimuli were presented at 50 dB SL. The behavioral results replicated previous temporal asymmetry findings for all three types of stimuli. There were significant effects of stimulus type and stimulus order in the MEG ON and OFF responses. Despite the stimulus type effect, the ramped tonal stimuli consistently elicited smaller and later N1m responses than the damped controls in both ignore and attend conditions. These data supports distinct cortical mechanisms for coding the stimulus type information and subjective duration information of the ramped vs. damped auditory stimuli.
An oscillatory template pitch model
Authors: Dahlbom David A. , Braasch Jonas
Published: April 2018

Traditional approaches to explaining missing fundamental and pitch-shift phenomena have relied on either the fitting of harmonic templates to spectral information (generally assumed to correspond to a neural excitation pattern), or by performing an autocorrelation-based calculation on temporal information. In this paper, an alternative approach relying on the dynamics of phase-locking oscillators is proposed. Rather than applying some decoding procedure, such as spectral analysis or autocorrelation, a pitch estimate is given by the state (firing frequency) of an appropriately excited oscillator in a template structure operating on peripheral information. This approach is shown to reproduce many of the classical pitch shift-phenomena. In addition to a direct implementation in terms of phase-locking oscillators, a simplified model consisting of arrays of adaptive templates, operating directly on timing information, is also presented. This latter approach offers a straightforward way to tune the model in accordance with existing psychoacoustical data and suggests an approach to modeling pitch strength and multiple f0 detection. The overall goal is to suggest the advantages of a modeling approach that relies on arrays of tuned, adaptive elements which are physiologically-inspired, though not intended to be detailed representations of precise physiological components. [Work was supported by NSF BCS-1539276.]
Pitch synchronous speech analysis for the assessment of subjects with Parkinson’s disease
Authors: Appakaya Sai Bharadwaj , Sankar Ravi
Published: April 2018

Analysis of speech samples from subjects with Parkinson’s Disease (PD) is a field of growing research interest. Studies in this field predominantly include pitch-based features with the intuition that PD affects the movement of musculature involved in speech production. These features are usually extracted on a segment of fixed length that traverses over the entire speech sample. This methodology, however, gives the net estimate of the feature over each segment and cannot account for the fast variations that transpire before and after a vocal fold closure. In this paper, we present a pilot study with the focus on in-depth pitch synchronous analysis that can fill-in the gap by capturing the said variations. Speech samples from 22 patients are preprocessed and used for analysis. Data that can pin point the precise indices of the vocal fold closures for each cycle are extracted in pre-processing and features that can capture the swift variations are extracted from every cycle and used for analysis. The results show a good margin in features between PD and healthy speech that reinforced the intuition.
A pitch encoding model based on the intrinsic oscillation circuit: Effects of the time constant and input stimulus types
Authors: Tsuzaki Minoru , Maki Katuhiro
Published: April 2018

Many temporal models for pitch perception have adopted a configuration of "delay-lines and coincidence detectors" after the cochlear filtering. Autocorrelation functions are a usual way of its implementation. However, a series of experiments by the authors' group have revealed that the perceived pitch would shift upwards by the effect of aging. Because the autocorrelation simply represents the time intervals statistics in the physical domain, the aging cannot affect this statistics. Therefore, a further pitch encoding process where the physical (physiological) temporal intervals are mapped against any internal reference in the brain. We propose a model comprised of bank of self-oscillatory circuits and the coincidence detectors. The periods of oscillations are intrinsic characteristics of the neural circuit. The proposed model could pick up the fundamental periods of a various types of stimuli, i.e., pure tones, missing fundamentals and iterated ripple noises. To check an effect of aging, the changes in the time constant of the temporal waveform of the oscillation was investigated. Although the shortest sensitive period increased due to the longer time constant, the age-induced pitch shift could not be predicted. It is necessary to assume a systematic lengthening of the period of each oscillation to predict the pitch shift.
Informational masking of calm speech targets by emotional speech maskers
Authors: Morgan Shae D.
Published: April 2018

Recent research suggests that some types of emotional speech are more intelligible than others when presented in background noise (Dupuis & Pichora-Fuller, 2015). Yet, emotional speech can often be present as the background noise itself. Attentional mechanisms and auditory stream segregation capabilities likely impact target word recognition in these situations with emotional speech maskers. The present study examined calm target sentences in masking background combinations of four emotions (calm, sad, happy, and angry) and two masker types (2-talker babble and speech-shaped noise). The emotion categories differ from one another on perceptual dimensions of activation (low to high) and pleasantness (unpleasant to pleasant). Speech-shaped noise maskers were spectrally and temporally similar to the 2-talker babble maskers. Performance was compared between the two masker type conditions to quantify the amount of informational masking induced by different emotional speech maskers. Furthermore, the number of target-masker confusions were identified for each masker emotion and subsequently analyzed. Results showed lowest target recognition with calm speech maskers, consistent with auditory stream segregation framework; however, confusions and informational masking were high for angry and happy speech maskers, which suggests that auditory attention to high-arousal stimuli may have influenced performance.
Modified two-component Shepard tones and their application to sine wave speech
Authors: Nissenbaum Jon
Published: April 2018

Sinewave Speech (SWS), consisting of several frequency-modulated sinusoids representing vocal tract formants, elicits perception of words/sentences, making it useful for studying the perceptual basis of speech. However, SWS contains no information relevant for pitch perception, making it a poor tool for investigating tone languages or prosody (Remez & Rubin, 1993, JASA94; Rosen & Hui, 2015, JASA138). The objective of this study was to develop a method for creating modified SWS replicas adding a minimal cue for pitch. The lowest sinusoid was replaced with a “modified Shepard tone:” a tone formed from a bandpass whose center frequency tracks F1, wide enough at any timepoint for exactly two harmonics of an independently specified f0 contour. It has been shown (Ritsma 1962, JASA34, Smoorenburg 1970, JASA48, Houtgast 1976, JASA60) that tones consisting of 1–3 harmonics elicit perception of a missing fundamental. An initial experiment confirmed that a bandpass whose center frequency fell from 700 to 400 Hz over 400 ms, intersected with harmonics of a rising f0 (85–185 Hz), elicited a strong perception of a rising contour, and vice versa. A second experiment replaced F1 in a set of SWS replicas with these two-component tones and elicited robust perception of contrasting pitch contours.
Gliding ripple speed thresholds for rippled spectra
Authors: Supin Alexander , Milekhina Olga , Nechaev Dmitry
Published: April 2018

Rippled noise is a productive model of natural signals with complex spectrum patterns. It was used as a test signal to measure spectrum-pattern resolution both in normal-hearing listeners and in hearing-impaired listeners and users of cochlear implants. However, a variety of natural auditory signals feature combined spectro-temporal patterns. These signals may be modeled by rippled noise with "gliding" ripples. In the present study, ripple gliding speed thresholds were measured in normal-hearing listeners. The highest gliding speed (expressed in oct/s or ripples/s) at which the gliding ripple pattern could be distinguished from a non-rippled noise was determined. The ripple gliding speed threshold expressed in ripple/s was inversely-proportional to the ripple density (ripples per octave, RPO); it decreased from approximately 400–500 ripple/s at RPO of 1/oct to approximately 50 ripple/s at RPO of 10/oct. Expressed in oct/s, the threshold decreased from 400 to 500 oct/s at RPO of 1/oct to 5 oct/s at RPO of 10/oct. Thus, the ripples fused into non-rippled spectrum at gliding speed more than 400 to 500 Hz/oct. At this speed, 400 to 500 ripples per second glide through an octave frequency band. [Work supported by The Russian Science Foundation, Grant 16-15-10046.]
Masking of synthesized vowel sequences: The potential roles of perceptual segregation
Authors: Shen Yi , Pearson Dylan
Published: April 2018

Modulation masking is known to impact speech intelligibility, but it is not clear how this phenomenon interacts with the perceptual segregation between the target speech and background noise. Using an experimental task in which listeners identified synthesized-vowel sequences in amplitude-modulated noises, a previous study from our laboratory found few signs of modulation masking, contrary to the findings of speech-on-speech masking experiments. It is hypothesized that modulation masking at a low rate (<6 Hz) may reflect failures of segregating the target speech from the noise. The current study systematically removed segregation cues and evaluated the amount of modulation masking. These segregation cues included the periodicity in the temporal fine structure of the target vowel sequences (in Exp. I) and the temporal regularity of the vowel sequences (in Exp. II). Results will be discussed in terms of the potential interactions between modulation masking and perceptual segregation.
Human inference of force from impact sounds: Perceptual evidence for inverse physics
Authors: Traer James , McDermott Josh
Published: April 2018

An impact sound is determined both by material properties of the objects involved (e.g., mass, density, shape, and rigidity) and by the force of the collision. Human listeners can typically estimate the force of an impact as well as the material which has been struck. To investigate the underlying auditory mechanisms we played listeners audio recordings of two boards being struck and measured their ability to identify the board struck with more force. Listeners significantly outperformed models based on simple acoustic features (e.g., signal power or spectral centroid). We repeated the experiment with synthetic sounds generated from simulated object resonant modes and simulated contact forces derived from a spring model. Listeners could not distinguish synthetic from real recordings and successfully estimated simulated impact force. When the synthetic modes were altered (e.g., to simulate a harder material) listeners altered their judgments of both material and impact force, consistent with the physical implications of the alteration. The results suggest that humans use resonant modes to infer object material, and use this knowledge to estimate the impact force, explaining away material contributions to the sound.
Perceptual consequences of cochlear synaptopathy in middle age
Authors: Flesher Brooke , Mai Alexandra , Dougherty Kelsey , Simpson Jennifer M. , Heinz Michael G. , Bharadwaj Hari M.
Published: April 2018

It is known that as the body ages, listening in noisy situations becomes increasingly more difficult. Middle-aged people have more difficulty than younger people in complex listening environments, even with similar audiometric thresholds. One hypothesis for why this might be is age-related cochlear synaptopathy. Cochlear synaptopathy has been robustly observed to occur with normal aging in animals, and in post-mortem studies of human temporal bones harvested at different ages. However, there are currently no clinical assessments to measure cochlear synaptopathy or the perceptual consequences of this phenomenon. Currently, we are evaluating a battery of clinical and laboratory measures by comparing young and middle-aged listeners with matched audiometric thresholds within the normal range. The battery includes both objective physiological measures that correlate with synaptopathy in animal models, and perceptual measures that hypothetically may be sensitive to synaptopathy-mediated loss of redundancy in afferent coding. Here, we discuss our initial findings within these parameters.
Brain potentials to speech perception in noise for patients with schizophrenia
Authors: Mi Lin , Wang Le , She Shenglin , Li Haijing , Liu Chang , Zheng Yingjun
Published: April 2018

Schizophrenia is characterized with a series of cognitive impairment, including basic information processing such as auditory and speech perception. Especially, patients with schizophrenia experienced additional challenge for speech perception in noisy environment. In this study, brain activity in response to speech sounds was measured in quiet and 6-talker babble conditions from 25 schizophrenia patients and 20 healthy subjects. A double-oddball paradigm was employed, in which /ba/ was played as the standard stimulus with /da/ and /bu/ as the deviant stimuli. Results showed that the schizophrenia group had lower amplitude and longer latency of mismatched negativity (MMN) compared with control group in both the quiet and babble conditions. In addition, there was a significant interaction effect between listening condition and listener group, i.e., the 6-talker babble exerted greater disturbance for schizophrenia. Moreover, the analysis of theta band oscillation in the time window of MMN also supported the above results. These findings indicated that the deficits in the pre-attentive automatic auditory processing in the patients with schizophrenia may underpin their speech perception difficulty in the daily noise environment.
Pupillometry as a measure of auditory cognitive processes and listening effort
Authors: Almaraz Damian , Carlson Brock , Grafelman Elaine , Ingalls Jacob , Quintanilla Yadi , Vu Hieu-Trung , Loebach Jeremy
Published: April 2018

Although many people with hearing impairments can accurately recognize words and sounds with proper treatments (hearing aids or cochlear implants), they often report fatigue and stress from doing so. These individuals need to exert more auditory cognitive processing effort to hear well, especially in adverse listening environments or when engaging in competing tasks. We hypothesize that the allocation of these auditory cognitive resources, or auditory cognitive “X-Factors,” can explain variability in outcome across cochlear implant users. To find the “X-Factors,” we use pupillometry as a physiological measure of cognitive load across auditory cognitive domains including short term memory (forward digit span) working memory (backward digit span), cognitive load (Paced Serial Addition Task), listening effort (speech in noise tests) and personality traits (motivation, self-efficacy, and adaptability). A custom-built eye tracking system using Pupil Labs software provides a cost-effective, dynamic, and fully mobile system to collect data in real time. Initial data from aging adults indicate significant correlations between cognitive abilities, pupil dilation, response strategy, and auditory performance. Understanding the “X-Factors” will help inform training and rehabilitation for hearing impaired individuals and cochlear implant users.
Estimating the duration of a refractory period in perceptual learning
Authors: Clain Alex E. , Wright Beverly
Published: April 2018

Auditory skills improve with practice. Producing across-day learning requires a sufficient number of trials per session; additional trials in the same session produce no additional improvement. Thus, trials appear to integrate within a session to reach a learning threshold, after which there is a refractory period during which trials do not contribute to learning. The refractory period duration must be <24 hours because training on consecutive days yields learning each day, but its exact duration is unknown. To narrow the range of possible durations, we trained young-adult, normal-hearing listeners on a basic auditory task (interaural-level-difference discrimination) either for two sessions of sufficient training separated by 30 minutes (n = 10) or 10 hours (n = 10), or for just one session (n = 15), and assessed their learning on the next day. The 30-minute group learned no more than the single-session group, indicating the second session did not aid learning, whereas the 10-hour group learned more than the other two groups, indicating the second session provided additional benefit. These results suggest that the refractory period lasts >30 minutes, but <10 hours, and does not require sleep to reset. Knowledge of the refractory period duration will improve the efficiency of perceptual training for typical and clinical populations.
Inter-digital transducers activated acoustic streaming in viscous liquid
Authors: Chen Chuyi , Zhang Peiran , Mao Zhangming , Gu Yuyang , Costanzo Francesco , Huang Tony Jun
Published: April 2018

Acoustic streaming induced by surface acoustic waves (SAWs) has been widely utilized in various medical and biology applications. For most of the applications, the microfluidic channel is attached to a piezoelectric substrate where the inter-digital transducers (IDTs) are fabricated on it to activate acoustic waves. The acoustic waves would propagate along the substrate surface and generate the “leaky wave” in the channel which causes the acoustic streaming. However, few studies are conducted to analyze the vibration mode of the substrate in the IDTs area and the following phenomenon (e.g., acoustic streaming generated by substrate vibration). In this study, we demonstrate a novel method which includes both simulation and experiment results to identify the substrate vibration and corresponding streaming while the liquid is loading upon the IDTs directly. With this method, we show that the acoustic streaming on top of the IDTs area has a “stagnation point” with a velocity potential to trap and manipulate the objects floating on the surface of the liquid, which is promising in many contactless biomedical applications.
Nonlinear resonant ultrasound spectroscopy using electromagnetic excitation
Authors: Gregg Joshua F. , Anderson Brian E.
Published: April 2018

Nonlinear resonant ultrasound spectroscopy (NRUS) is a method that can be used for detecting microcracks in structures. NRUS detects shifts in resonance frequencies versus excitation amplitude. Excitation of the sample is typically done with a piezoelectric transducer. We have been applying an electromagnetic excitation developed for resonant ultrasound spectroscopy [S. Garrett, J. Acoust. Soc. Am. 88(1), 210–221 (1990)] as an alternative for NRUS excitation. It involves gluing a coil of wire onto the end of a rod-shaped sample and placing it in a magnetic field. By controlling which part of the coil is in the strongest part of the magnetic field, we can control the principle direction of the driven oscillations in the rod. This method allows us to selectively excite longitudinal, torsional, and bending vibrations and measure the nonlinear properties of the sample for each type of vibration. We have applied this electromagnetic method to measuring the nonlinear properties of Berea sandstone, and we plan to use it to detect stress corrosion cracking in stainless steel samples. The purpose of this presentation is to illustrate the usefulness of the electromagnetic method.
Thermoacoustic instability in solid media
Authors: Hao Haitian , Scalo Carlo , Sen Mihir , Semperlotti Fabio
Published: April 2018

The exploration of thermoacoustic oscillations can be traced back to the 19th century when Sondhauss (1850) performed an experimental investigation that marked the birth of modern thermoacoustic research. Since then, several practical applications of the basic thermoacoustic effect were explored and ultimately led to the design of engineering devices such as heat engines or refrigerators. This fascinating mechanism was believed to occur only in fluids while our study shows theoretical and numerical evidence of the existence of thermoacoustic oscillations also in solid media. Although this mechanism shares common aspects with the more familiar thermoacoustics of fluids, our analysis shows that the underlying physical mechanism presents some important and non-trivial differences with the traditional theory. The discovery and validation of this mechanism may lead to new ideas enabling the development of the next generation of ultra-compact and robust solid-state thermoacoustic devices for direct thermal-to-mechanical energy conversion, and vice versa.
Acoustic correlates of the four-way laryngeal contrast in Marathi stops
Authors: Dmitrieva Olga , Dutta Indranil
Published: April 2018

As many of its geographical and typological neighbors, Marathi demonstrates a four-way laryngeal contrast in stop consonants, which includes plain voiced and voiceless stops as well as aspirated voiceless stops and typologically rare aspirated (breathy) voiced stops. The present study investigates the acoustic correlates of the laryngeal contrast in word-initial velar stops in Marathi. Thirty three native speakers of Marathi were recorded in Mumbai, Maharashtra, India. Positive and negative Voice Onset Time (VOT), fundamental frequency at the onset of voicing (onset f0), and spectral intensity as a measure of breathiness during the following vowel were investigated as correlates of laryngeal distinctions. Preliminary results show that all four stop categories are well-distinguished via VOT and onset f0 measures. Initial spectral intensity measurements suggest that breathiness in Marathi stops is largely contained in the release and does not extend far into the following vowel, unlike what has been found in Hindi (Dutta, 2007). The results will be discussed with respect to the typology of voicing contrast across languages, specifically the relevance of VOT distinctions and the use of onset f0, and compared to relevant findings for typologically similar languages.
VOT in Tibetan is conditioned by tone
Authors: Geissler Christopher A.
Published: April 2018

Several South Asian languages exhibit interactions among tone and consonant phonation, including Tamang (Mazoudon 2014) and Gurung (Ronkos 2015). In Central Tibetan, oral stops present a four-way contrast between two voicing/aspiration categories split across two lexical tones, high and low/rising. Across tones, previous analyses propose either a two-way contrast between unaspirated and aspirated stops (e.g., Dawson 1980), or a three-way contrast between voiced, unaspirated, and aspirated series (e.g., Denwood 1999), though acoustic measurements are lacking. This study recorded 19 native speakers of Tibetan in Kathmandu, Nepal, producing words exemplifying the phonological contrasts in stops and high/low tones. VOT measurements showed similar values for the unaspirated stops in both tonal environments, but a longer VOT in high-tone aspirated stops (46 ms) than low-tone aspirated stops (30 ms), or three different positive VOT values. That this three-way surface contrast cross-cuts tonal categories suggests an underlying two-way aspiration contrast. The apparent contrast between middle-VOT and long-VOT series results from the presence of a phonologically-specified high tone, which causes a lengthened VOT. This provides evidence for the conditioning of apparently-segmental characteristics by tone.
Within-category variation in production of Hindi and English stop consonants
Authors: Hauser Ivy
Published: April 2018

This paper addresses the broad question of how phonological structure affects phonetic production using within-category variation of multiple phonetic cues in Hindi and English stop consonants. The intuitive hypothesis, formalized in Dispersion Theory (Lindblom, 1986) is that languages that have more phonological contrasts along a single phonetic dimension should have relatively less within-category variation along that dimension. Hindi (four stop contrasts per place of articulation) speakers are therefore predicted to exhibit less within-category variation in production relative to English (two contrasts per place) speakers. This was observed in the results of Hauser (2016) who examined VOT variation of voiceless aspirated stops in these languages. The present study builds on those results and examines F0 as a second cue to the voicing contrast. The F0 results do not conform to the prediction that Hindi speakers should exhibit less variation. There was no difference in F0 variation between the Hindi and English speakers, yet there were significant differences in the amount of within-category F0 variation among the individual Hindi speakers (Levene’s Test p < 0.001). It is argued that this is because F0 acts as a secondary cue to the voicing contrast. Speakers can exhibit greater and individualized levels of variability in F0 without adding perceptual confusion because the primary cue (VOT) remains distinct.
The length of copied consonants in geminates, total assimilation, and ambisyllables
Authors: Burke Mary , Robinson Melissa A.
Published: April 2018

Lamkang is an under-documented endangered Kuki-Chin language of the Northeast India spoken in 40 villages spread across Manipur’s Chandel district with under 10,000 Lamkang-Naga speakers (Ethnologue 2014). In Lamkang, doubled consonants have three different sources: (1) gemination when stems are followed by enclitics of the shape V; (2) total assimilation of enclitics to stem codas; (3) ambisyllables in prefixes of the shape CV (where V is an epenthetic vowel). We examine the acoustic properties of the doubled consonants in these three morphological environments to show that the length of the closures reflect the morphological derivational history. The paper investigates a method for measuring doubled consonant length: We measure from peak intensity of vowels on either side of the consonant closure, rather than the length of the closure. Orthographic practice reflects these differences as doubled consonants in the prefixes are shorter than the phonologically derived consonants with enclitics. Copied consonants are written for enclitics but not in prefixes.
Temporal-spatial and source level distributions for a repertoire of fin whale vocalizations in the Norwegian Sea observed with a coherent hydrophone array
Authors: Garcia Heriberto A. , Wang Delin , Zhu Chenyang , HUANG WEI , Kaplan Anna , Ratilal Purnima
Published: April 2018

The vocalizations of the fin whale are detected, characterized and localized over instantaneous wide areas of the Norwegian and Barents Seas using a large-aperture densely-sampled coherent hydrohone array via the passive ocean acoustic waveguide remote sensing (POAWRS) technique from observations in late winter to early spring 2014. The fin whale vocalizations are comprised of their characteristic 20 Hz pulses, interspersed by 130 Hz upsweeps, less abundant 30-100 Hz downsweep chirps and 18-19 Hz centered backbeats. The time-frequency characteristics of these vocalization types and their diel occurrence rate time-series are quantified in three distinct regions of the Norwegian Sea, off the coasts of Alesund, Lofoten, and the Northern Finnmark. Their vocalization rates are a factor of roughly 5 times and 17 times larger respectively for the 20 Hz and 130 Hz centered vocalizations off Northern Finnmark than the other regions. The vocalization rate spatial density distributions, source level distributions and probability of detection (PoD) regions are estimated for the 20 Hz and 130 Hz vocalizations. Highly intense 20 Hz pulses from closeby fin whales are received with their first-order harmonics centered at 40 Hz with twice the bandwidth but 30 dB lower source levels, indicating a nonlinear mechanism for their production.
Signal compression technique in decomposition of arrivals having different speed of sound propagation through human lungs in the frequency range of 10–19 kHz
Authors: Korenbaum Vladimir , Shiryaev Anton , Kostiv Anatoly , Safronova Maria
Published: April 2018

The unexpected phenomenon of sound transmission through human lungs at frequencies above 10 kHz with a speed of about 1000 m/s was revealed by Rueter et al., 2010. The objective is a study of characteristics of sound transmission in human lungs in the frequency range of 10–19 kHz using signal compression technique. The 14-channel receiving apparatus was used. Chirp signals 10–19 kHz (6 min) were emitted into human thorax by small shaker. Sound propagation in human lungs was studied in paths with opposite chest positions of shaker and sensors in 4 volunteers. An existence of low-speed arrivals with propagation velocities of 150–50 m/s, which amplitude and/or velocity is inversely dependent on the air-filling of lungs (inspiration/exhalation) has been revealed. These arrivals may be treated as a result of sound propagation mainly through the lung parenchyma. On the contrary, the amplitudes of high-speed arrivals with velocities of 150–1000 m/s are enhanced with a decrease in air-filling of lungs. They may be connected to the sound propagation mainly through high-density tissues of thorax. The results are promising for medical acoustic visualization of local reduction in air-filling/ventilation of lung parenchyma. [This study was supported by the RFBR grant 16-08-00075.]
Underwater fiber optic transducer
Authors: Darnton Aaron
Published: April 2018

Fiber optic sensors have been used in various configurations including interferometric, Bragg grating, and Rayleigh scattering approaches. In this work, the Rayleigh approach is considered for use as a hydrophone. This approach transmits light along a single fiber and utilizes the backscattered light to infer small strains in the fiber. Typically in-water use of this type of optical acoustic receiver has been limited due to the gross motion of the fiber in the water. The gross motion tends to wash out the acoustically driven strains of interest. Additionally, sensitivity can be relatively low in this approach. This work considers sensing on a section of fiber wrapped around a mandrel for the purpose of increasing sensitivity as well as reducing the effects of gross motion.
Case study of acoustics in two very large atriums
Authors: Foulkes Timothy
Published: April 2018

Two recent projects have involved very large spaces with predominantly hard finishes. One assignment was to develop an acoustic treatment plan for an existing six story interior courtyard within an office tower. This space, a very formal design finished in marble, wood paneling, and glass, had a 7 second reverberation time. The courtyard was available as a lounge space to all tenants of the building but was barely utilized. We were part of a design team hired by the building owners to update the courtyard and make it more user friendly, including improvement in the acoustics. The other atrium was part of a new project—a seven story glass enclosure with a concrete floor. This atrium serves many different functions including the main entrance and security lobby, dining space, informal meeting space, and lounge. The acoustics were mitigated by the irregular shape, areas of carpet on the balconies, and limited areas of acoustic paneling. The new atrium is a success and it has become the living room and hub for this large building. It is well used throughout the work day for all of the purposes mentioned above and more. Renovations for the other space are still in design as of the abstract deadline, but there may be finished in time for the Spring ASA meeting. The presentation will include a discussion of the dimensions and finishes, acoustic priorities, design challenges, acoustic measurements, and subjective comments.
Measured acoustic conditions in the common spaces of two educational buildings at the University of Nebraska–Omaha
Authors: Underwood Samuel H. , Wang Lily M.
Published: April 2018

This paper presents results from an acoustical case study of the atria, corridors, stairways, and other common spaces within two buildings located on the campus of the University of Nebraska-Omaha: the Peter Kiewit Institute and the Barbara Weitz Community Engagement Center. Both buildings, while educational in nature, differ drastically in acoustical design. Impulse responses, noise levels, and transmission loss in both facilities are measured and the resulting acoustic metrics are compared to recommended values for the respective spaces. Descriptions of each building’s architectural features are presented and linked to the measurement results. In particular, many spaces in the Peter Kiewit Institute were designed to expose the building systems, and the lack of acoustical products such as acoustical ceiling tile results in higher noise levels than normally expected. The Weitz Center, however, was designed with great emphasis placed on achieving optimal indoor environmental conditions. The results of this case study support the importance of appropriate acoustic design atria, corridors, stairways, and other common spaces in educational settings.
The architectural rejuvenation of Canada’s National Arts Centre: The function of pre-function
Authors: Glosemeyer Petrone Robin S. , Mayell Marcus R.
Published: April 2018

When Canada’s National Arts Centre opened in 1967, the Brutalist architecture style of its era yielded a fortress for the arts. As Canada celebrates its sesquicentennial, a $110M (Canadian) architectural rejuvenation process is transforming the inward facing fortress into alluring beacon at the heart of the capital. Expanded public spaces enveloped in transparent facades form multiple pre-function spaces that visually spill into one another to convey the constant activity of Canada’s incubator for the performing arts to the patrons within and the surrounding city. The desire for visual transparency, the building’s designation as a National Historic Site of Canada, and need for simultaneous programming of the performance and pre-functions spaces provided no shortage of acoustic challenges.
History of technology for studying animal sound and communication
Authors: Mellinger David K.
Published: April 2018

New technology has always been used to listen to, study, and understand animal sounds. Early recording devices in the 1870s employing wax cylinders and discs were quickly employed for recording nature sounds. Underwater listening devices from the 1910s captured marine animal sounds; interest in these sounds increased greatly after World War II, when naval advances made underwater sound accessible to sonar operators who noted the presence of cetacean sounds. Microphone technology advanced to the point where ultrasonic and eventually infrasonic signals were recorded. Frequency separation and analysis was facilitated by the invention of the vocoder in the late 1930s, which separated sound into a number of frequency bands and enabled, for instance, the discovery of multiple sources of sound (more than one syrinx) in bird vocalizations. The greatest leap in frequency separation came with the discovery of the Fast Fourier Transform and its application on digital computers for making spectrograms; since the 1970s, these simple graphic displays have made it possible to look at sound signals statically, greatly facilitating analysis. Advances in digital multi-channel recording have improved our ability to localize animals and study communication networks. Advances in analysis software continues to improve our ability to interpret sounds of animals.
The last decade of bioacoustics at the Office of Naval Research
Authors: Weise Michael
Published: April 2018

The goal of the ONR Marine Mammals and Biology (MMB) program is to enable Navy to and meet operational training and testing objectives in an environmentally responsible and legal manner. The ONR Marine Mammals and Biology program invests in Monitoring and Detection topic with the goal is to improve marine mammal monitoring capabilities over current methods. Develop new and existing technology such as passive acoustics, IR, and others. Recent research efforts on passive acoustics include the development and testing of new autonomous hardware platforms and signal processing algorithms for detection, classification, and localization of marine mammals. Ultimately, the ONR goal is to adapt those algorithms for use on a variety of fixed, towed, floating, and profiling platforms. For example, over the last several years ONR has adapted the use of autonomous ocean gliders for marine mammal monitoring to create the desired capability of persistent, autonomous, passive acoustic monitoring of an area for marine mammal presence and abundance to provide timely, reliable, accurate, and actionable information to support marine mammal mitigation and monitoring. A key goal of ONR sponsored technology development is making the technology available to the broader Navy and research communities.
History of bioacoustics research on aquatic and marine organisms in Hawaii
Authors: Au Whitlow
Published: April 2018

Modern bioacoustic research with aquatic animals began in Hawaii in the 1968–1969 period when three independent programs started almost simultaneously. Two faculty members began studying various facets of hearing in fish at the University of Hawaii. Another faculty member from a different department established a laboratory in which dolphin hearing and echolocation were among some of the topics studied. The Navy started a dolphin facility to train dolphins to perform Navy related tasks. The Navy program also included research on dolphin echolocation including a study comparing the performance of two dolphins and a Straza-500 CTFM sonar in target detection. The Navy facility closed in 1993 but some of the bioacoustics research was transferred to the University’s Hawaii Institute of Marine Biology on Coconut Island about a mile from the former Navy facility in the same bay. The HIMB program expanded into field research with spinner dolphins and humpback whales, and passive acoustic monitoring of marine organisms. The local National Marine Fisheries Service of NOAA became a close partner in the PAM development and studies. This presentation will focus of the bioacoustic research performed with marine mammals highlighting some of the more important findings and contributions to the field.