bluuebunny/crossref_metadata_2025 huggingface dataset:
Determining auditory brain stem response threshold using an adaptive stimulus selection procedure
Authors: Petersen Erik A. , Shen Yi
Published: May 2022

Auditory brain stem response (ABR) measurements provide a method to determine the hearing threshold of laboratory animals and humans who are unable to provide behavioral responses to auditory stimuli. Determining hearing threshold using ABR typically requires a large number of pre-selected frequency and stimulus levels, which may not be the most efficient method to sample the stimulus space. The goal of the current study is to develop an adaptive procedure that determines in situ the stimulus that will provide the best estimate of the threshold, based on data collected earlier in the procedure. A Gaussian Process model is iteratively fitted after each testlevel, and the subsequent test level is chosen at the interim threshold estimate predicted by the current model fit. Simulations of the adaptive procedure were conducted using previously collected toneburst ABR measurements from mice presented at 5 dB increments from 0 to 80 dB at seven frequencies ranging from 4 to 32 kHz. The thresholds determined by this procedure were compared to those produced by human raters who viewed the response at all stimulus levels. Initial results indicate that the threshold may be accurately estimated utilizing fewer stimuli levels than current methods, thereby reducing the duration of the measurements.
Relationship of noise history to perceived loudness and physiological arousal from noise
Authors: Pinaula-Toves Alanalyn N. , Nelson Peggy , Gianakas Steven P. , Sullivan Jessica , Winn Matthew B.
Published: May 2022

Chronic exposure to noise is a well-documented health hazard (Suter, 1991). In this study, we investigated whether an individuals’ self-reported noise history (exposure, sensitivity, and annoyance) correlated with noise-elicited physiologic arousal. We measured pupil dilation responses and loudness judgments to varying types of noise and related those to self-identified noise history. We hypothesized that increased history of exposure or annoyance would be correlated with perceived loudness and arousal from noise. Five colors (spectra) of noise were generated with the same sound pressure levels within the band 1000–4000 Hz but with different slopes of spectral energy below and above the band. Changes in participant pupil dilation responses elicited by each noise type were used as an assessment of physiological stress response to noise stimuli. Participants also adjusted the loudness of two randomized noise spectra until they were determined to be of equal loudness. Preliminary data suggest that the perception of loudness and levels of arousal differed depending on the color spectrum of noise. Relationships between the loudness judgments, self-reported noise history, and observed physiologic data will be further discussed. Results have implications for understanding the behavioral and physiological effects of chronic exposure to noise. [Robert Young, NIDCD R01DC017114 (Winn).]
The difference between using context to predict versus using context to repair: a study of listening effort
Authors: Smith Michael L. , Winn Matthew B.
Published: May 2022

Semantic context in sentences has been shown to increase intelligibility and reduce listening effort. However, context has typically been tested in situations where it is used to predict upcoming words rather than repair earlier words. The current study attempts to directly compare predictive versus retroactive context for the first time for the same listeners in the same study. We hypothesized an increase in effort for retroactive context compared to the elevated effort of predictive context. Cochlear implant and Normal Hearing listeners heard sentences where a single content word was masked by noise, either early in the sentence (requiring retroactive repair) or later in the sentence (where it was predicted by earlier words). Changes in pupil dilation were measured as an index of listening effort linked with the moment of each word and its context. Effort increases when context is used to repair an earlier missing word, even if intelligibility is perfect. There is a smaller increase of effort when the missing word follows context that enabled prediction of the word. This study provides a novel approach in directly comparing the mental cost of using context to repair versus predict misperceived words in a sentence.
Aging effects on binaural listening and other auditory system assessments
Authors: Walker Kerry A. , Sammeth Carol A. , Greene Nathaniel , Klug Achim , Tollin Daniel
Published: May 2022

Older listeners are known to have decreased sound localization and hearing in noise abilities compared to young listeners, even when exhibiting clinically normal hearing. We hypothesize that these deficits may be related to decreased temporal precision of neural activity in the sound localization processing pathway, and/or other central auditory system deficits involving more complex functions such as speech recognition. Presented here are preliminary results from a study underway on the impact of aging on auditory functioning, and in particular, binaural processing. Subjects range from 21 to 89 years of age, have normal or near normal-hearing sensitivity, and are being evaluated on assessments of auditory system integrity and behavioral performance. Primary outcome measures include speech understanding in noise, auditory brainstem responses (ABRs) and the calculated ABR binaural interaction component, behavioral measures of spatial acuity, and a subjective questionnaire of hearing handicap. Secondary measures include temporal fine structure and spectro-temporal modulation sensitivity tests, otoacoustic emissions, and electrocochleography. In addition, extended-high-frequency hearing thresholds are measured and working memory assessed. Early results show an aging effect across decades of life on several of these measures. Greatest aging effects are seen in the more adverse listening conditions from behavioral testing. [Support: R01-DC017924.]
Two kinematic gains underlying the organ of Corti mechanotransduction
Authors: Macic Anes , Lin Wei-Ching , Nam Jong-Hoon
Published: May 2022

The organ of Corti (OoC) is the sensory epithelium in the mammalian hearing organ where vibrations are encoded into neural signals. The OoC vibrates due to external and internal agitations. Externally, differential fluid pressures across the OoC cause vibrations. Internally, actuator cells (outer hair cells) are known to boost the vibrations. These two agitations result in distinct vibration patterns. Eventually, these vibrations deflect the stereocilia bundle to activate mechanotransduction channels in them. How OoC vibrations result in the hair cell mechanotransduction is critical to hearing research, but a fundamental information (kinematic gain) has not been quantified clearly. Using the optical coherence tomography, we measured 2-D vibrations of the OoC in cochlear turns acutely excised from young Mongolian gerbils. The excised tissues were stimulated either mechanically or electrically, which are comparable to external or internal agitations, respectively. The stereocilia deflection was estimated from relative motion between overlying and underlying structures. Two kinematic gains were defined. Passive kinematic gain represents the amplitude ratio between the stereocilia deflection and the basilar membrane transverse vibration. Active kinematic gain represents the amplitude ratio between the stereocilia deflection and the outer hair cell length change. (Work supported by NIH NIDCD R01 DC014685.)
Binaural brainstem and spatial hearing deficits in a guinea pig model of noise-Induced cochlear synaptopathy
Authors: Benson Monica A. , Peacock John , Greene Nathaniel , Tollin Daniel
Published: May 2022

Animal studies have revealed that moderate-level noise exposure can cause a permanent loss of ribbon synapses between inner hair cells and auditory-nerve fibers, but only temporary threshold shifts. Such noise-induced cochlear synaptopathy has been called ‘hidden hearing loss’ because while there is a significant degeneration of ribbon synapses, the resulting hearing dysfunction is effectively hidden from typical clinical assays. Here we used guinea pigs to study the mechanisms leading to hearing deficits resulting from a moderate noise. We measured distortion product otoacoustic emissions and auditory brainstem responses to assay peripheral hearing. We tested spatial hearing ability through the prepulse inhibition (PPI) of the acoustic startle reflex. PPI was used to measure hearing-in-noise ability, or spatial release from masking, as this task approximates the “cocktail party” effect. Finally, we performed immunohistochemistry to confirm synaptopathy. Results show that the noise exposure induces no permanent hearing threshold shift, but despite recovery of normal audibility, both behavioral and electrophysiological binaural hearing deficits persisted. Cochlear synaptopathy was objectively confirmed by visualizing the loss of ribbon synapses in the cochlea. The results demonstrate that cochlear synaptopathy causes deficits in brainstem circuits known to be critical for binaural and spatial hearing. [Work supported by Otolaryngology T32 DC012280.]
Pitch-timbre interactions as measured in discrimination and the frequency-following response
Authors: Anderson Ryan , Shen Yi , Shofner William P.
Published: May 2022

Perceptual interactions between pitch and timbre have been demonstrated repeatedly using discrimination tasks in psychoacoustics. The current study investigates whether the pitch-timbre interaction is reflected in neural signatures of pitch encoding in the brainstem. Listeners discriminated the pitch of harmonic tone complexes with low- or high-spectral centroids (SC) in a yes/no task. Fundamental frequency (F0) varied by one just noticeable difference (JND), while SC could be varied by two- or five- JNDs. Discrimination performance increased when both F0 and SC were higher as opposed to when one was higher, and one was lower. This suggests that higher SCs bias listeners toward “higher pitch” responses, replicating previous studies. Frequency-following responses (FFR) were obtained in response to the same stimuli from the same listeners. The recorded FFR signals were analyzed using autocorrelation functions, to evaluate the coding of periodicity, and the Fourier spectra, as an indicator of the encoded F0. The encoding of pitch-relevant information was similar for all stimuli, regardless of SC. Contrary to bias observed in pitch discrimination performance imposed by SC, the lack of a significant influence of SC in the FFR measurements suggests that the pitch-timbre interaction was not observed at the level of the brainstem.
Variance of alpha oscillation power corresponds to behavioral performance in spatial auditory attention
Authors: Richardson Benjamin N. , Shinn-Cunningham Barbara , Kwasa Jasmine
Published: May 2022

To analyze an acoustic stream from a desired location, the brain focuses spatial selective attention, which causes shifts in parieto-occipital alpha power (∼8i–12 Hz). We explored whether neurotypical (N = 10) and ADHD (N = 36) adults differ in performance and in the time course of alpha in a spatial attention task. Subjects reported the order of syllables presented in spatially separated streams while EEG was recorded. In each trial, subjects either maintained attention on a central “target” stream (focal attention) or reported the content of a possible “interrupter” from the left (broad attention). Previously, we found that performance correlates with individual differences in how strongly listeners suppress, in focal trials, event-related potentials elicited by the interrupter. We hypothesized that oscillatory alpha signatures would differ for focal and broad attention, reflecting top-down control of spatial attention. Instead, we found that higher consistency in alpha oscillations correlated with better behavioral outcomes. Rather than deploying spatial attention differently in focal and broad conditions, good listeners may use the same listening strategy in both, but be better in staying on task (i.e., overall “focus”). We propose that the unpredictable interrupter engages bottom-up attentional pathways that are functionally separate from previously demonstrated spatial attention steering mechanisms.
Comparison of click and chirp stimuli in evoking the binaural interaction component of the auditory brainstem response
Authors: Owrutsky Zoe , Tollin Daniel
Published: May 2022

Chirp stimuli enhance synchrony in the auditory nerve by compensating for frequency- and level-dependent delays accrued by the traveling wave in the cochlea. Chirps produce larger amplitudes in specific waves of the monaural auditory brainstem response (ABR). We test whether chirps increase the amplitude of the binaural interaction component (BIC) of the ABR, a potential biomarker for binaural hearing. ABR latencies were measured across multiple stimulus frequencies and intensities in chinchillas. Tone bursts (1–16 kHz) were presented ∼10 dB below to 50 dB above threshold. Latencies of ABR waves I-IV and BIC were plotted against frequency and fit to a power function: Tau = k*f(-d), where tau is latency, f is frequency, and k and d are constants. The values of k and d were used to construct chirps for three intensity-levels based on monaural ABR waves I and IV, and BIC. Monaural ABR latencies decreased with increasing frequency as expected from cochlear delay. Monaural ABR amplitudes were enhanced by chirps relative to clicks. Surprisingly, BIC DN1 latencies did not show a similar shift but rather appeared constant across frequency. Traditional chirp stimuli appear ill-suited for eliciting optimal BIC amplitudes. Traditional broadband clicks or non-traditional chirps may be preferable for evoking the BIC.
Syllable inference as a mechanism for spoken language understanding
Authors: Dilley Laura
Published: May 2022

A classic problem in spoken language comprehension is how speech is perceived as comprised of discrete words. A Syllable Inference account of spoken word recognition and segmentation is proposed, according to which alternative hierarchical models of syllables, words, and phonemes are dynamically posited. Estimates of context speech rate are combined with generative models, such that over time, models which result in local minima in error between predicted and recently experienced signals give rise to perceptions of hearing words. Evidence for this account comes from experiments using the visual world eye-tracking paradigm. Materials were sentences that were acoustically ambiguous in numbers of syllables, words, and phonemes they contained. Time-compressing, or expanding, speech materials permitted determination of how temporal information at, or in the context of, each locus affected looks to, and selection of, pictures with a singular or plural referent. Supporting our account, listeners probabilistically interpreted identical chunks of speech as consistent with a singular or plural referent to a degree that was based on the chunk’s gradient rate in relation to its context. These results support the Syllable Inference account that arriving temporal information informs inferences about syllables, giving rise to perception of words separated in time.
Perception of gender in children's voices
Authors: Holt Christopher E. , Fox Robert A. , Jacewicz Ewa , Arzbecker Lian J.
Published: May 2022

Research shows that gender in the voices of prepubescent children can be identified relatively well, despite the absence of reliable anatomical differences related to their vocal tract morphology. This implies that information about differences in girls’ and boys’ voices also resides in behavioral and cultural aspects of speech and not exclusively in the acoustic cues corresponding to anatomical differences. The observed improved gender identification (gID) for sentences over syllables suggests that longer stretches of speech provide listeners with a richer acoustic basis for their decisions. Here, we introduce two additional factors that may affect gID: speaking style and children’s dialect. Children (n = 92) ages 8;0–12;4 years, boys (n = 45) and girls (n = 47) from Ohio, Wisconsin, and North Carolina produced isolated syllables, read sentences, and spontaneous utterances. Listeners were young adults from Ohio. Expectedly, gID accuracy for sentences/utterances was greater (66%) than for syllables (55%), and for older than younger children. Dialect was a significant predictor for younger (but not older) children, with the highest gID for Ohio. Overall, spontaneous utterances did not provide more gender information than read sentences except for older children from North Carolina, suggesting that cultural traits in conversational dynamics can also be useful to listeners in gID.
Distal context rate effects attenuated by attention
Authors: Heffner Christopher C.
Published: May 2022

Listeners use the rate of speech at the beginning of a sentence to segment ambiguous words that occur later in a sentence. For instance, the sentence “the drab mermaids will join the clean medics smoothly” can also be perceived as ending with “medic smoothly” if the words at the sentence onset are slowed down, showing the effects of what has been termed distal context rate. Here, I report a set of studies that assess the extent to which distal context effects are subject to modulation by attention. We manipulated two types of attention: explicit attention (in the form of overt task instructions) and implicit attention (employing unnatural F0 contours to attract or distract). These were designed to focus listeners on or divert listeners from the word segmentation ambiguities present in the signal. The findings suggest that listeners who were cued to attend more to the word segmentation ambiguities were less affected by distal context effects than listeners who were cued to shift their attention away. This suggests that listeners who were cued to apply more “perception-oriented” attention (cf. McAuliffe and Babel, 2016) to experimental items may be less affected by context speech rate than those cued otherwise.
Dominance patterns in concurrent vowel recognition
Authors: Edwards David
Published: May 2022

When hearers encounter multiple people speaking at the same, they can often pick out the speech of one person from the others, but the mechanisms which they use in their acoustic discrimination process are not fully understood. To look into vowel discrimination processes, this project entailed combining sound files of minimal pairs generated by synthetic speakers. As a point of departure from many similar experiments, these files were standardized for pitch and intensity. Participants were asked to select the word they heard from a list of four potential words that shared the same beginning and ending consonants, differing only in the vowel. Participants were significantly more likely to select a word if its vowel had a higher F1 than the F1 of the other vowel of the combined audio file. Higher F2 and F3 frequencies and greater movement of F1 also contributed to increased selection rates, although not as much as the F1 ratio. Participants were also asked to describe a subset of the combined sound files. That task showed similar dominance patterns, such that participants were often unaware of the presence of one of the concurrent vowels.
Talker and sentence variability attenuates speaking rate normalization in speech perception
Authors: King Caleb J. , Sharpe Chloe M. , Shorey Anya E. , Stilp Christian E.
Published: May 2022

Speech perception is shaped by acoustic context effects, where acoustic properties of earlier (context) sounds influence categorization of later (target) sounds. These context effects are sensitive to talker characteristics. When context sentences were spoken by a different talker on each trial, spectral contrast effect (SCE) magnitudes affecting categorization of the target vowel were smaller than when sentences were spoken by a single talker [Assgari and Stilp, J. Ascoust. Soc. Am. (2015)]. Here, perceptual consequences of talker variability were examined in Temporal Contrast Effects (TCEs; also termed rate normalization). Each trial presented a context sentence (spoken at a fast or slow rate) followed by a target word varying from “deer” to “tier.” Context sentences were the same stimuli from Assgari and Stilp (2015): one talker speaking the same sentence on each trial, one talker speaking a different sentence on each trial, and 200 talkers each speaking a different sentence on each trial. TCE magnitudes significantly decreased between One Talker/One Sentence and One Talker/200 Sentences, and again between One Talker/200 Sentences and 200 Talkers/200 Sentences. Conversely, in Assgari and Stilp, talker variability diminished SCEs but sentence variability for a single talker did not. These results suggest that variability in different acoustic domains restricts speech perception.
Rapid speech adaptation in younger and older normal-hearing adults: Distributional and lexically guided learning
Authors: Cheng Ruoqian , Jongman Allard
Published: May 2022

In speech perception, when a primary acoustic cue (e.g., VOT) is ambiguous, listeners may increase the weight of a secondary cue (e.g., F0). In experiment 1, we compared the cue-weighting adjustment strategies across younger and older normal-hearing adults with a distributional learning paradigm. Two groups of native English listeners were exposed to voicing contrasts that were ambiguous in either VOT or F0. Additionally, listeners may access lexical information to help resolve the ambiguity in the acoustic signal. Older listeners have been reported to use lexical information to a greater degree than younger listeners. In experiment 2, using a lexically guided learning paradigm, we tested if younger and older adults differ in their use of lexical information when learning to interpret ambiguous acoustic tokens. There were four types of exposure, in which stimuli differed in lexical status (day-*tay; *doy-toy) and the acoustic ambiguity involved either only VOT or both VOT and F0. Preliminary results from younger normal-hearing, listeners showed significant speech adaptation effects, with a significant change in cue weights in distributional learning and salient lexical bias in lexically guided learning. More data will be collected from older adults to assess the extent of perceptual learning relative to younger adults.
Cents and Shenshibility: The role of reward in talker-specific phonetic recalibration
Authors: Mechtenberg Hannah , Luthra Sahil , Myers Emily B.
Published: May 2022

We, as listeners, encounter many challenges during speech comprehension that extend far beyond resolving ambiguities in the acoustic phonetic signal. An understudied component of naturalistic speech comprehension is how motivated a listener is to attend to various aspects of the speech signal. This includes, when listening to multiple novel talkers, whether we give talkers equal attention when adapting to their idiosyncratic productions. We asked if listener adaptation is influenced by an external reward that is intended to bias attention towards one talker versus the other. In a lexically guided perceptual learning paradigm, participants heard two talkers of different genders—“Jane” and “Austin”—with idiosyncratic productions of the /s/ and /ʃ/ fricatives. Participants were more likely to receive a small monetary reward for one talker than the other following correct responses during a phoneme-monitoring cover task. We hypothesized that participants would show greater phonetic recalibration for the more-rewarded talker than the less-rewarded talker; however, our results indicate that external reward may undermine learning for both talkers. The role of reward and motivation in talker-specific phonetic recalibration raises interesting questions for how these domain-general factors influence language processing more broadly.
Perceptual consequences of clear speech
Authors: Biro Tifani , Viswanathan Navin , Olmstead Anne J.
Published: May 2022

When faced with communication challenges talker often modify their way of speaking producing clear speech. In a production study we investigated how American English talkers adapt medial flaps (e.g., petal and pedal are pronounced as [ˈpɛÉ¾əl]) following miscommunications with a computer partner. When subjects said a word (e.g., petal) the computer either interpreted the word correctly or incorrectly (it guesses pedal, kettle or ???). Talkers produced longer words, vowels, and stop closure in response to an incorrect versus correct guess. Talkers also changed their flapped productions to stops and lengthened stop closures more following voicing errors compared to other error types. Thus, talkers’ adjustments appear to depend on the miscommunication type. Next, we investigated how listener perceptions were influenced by the talkers’ adjustments. Listeners heard talkers’ productions and indicated what they heard. Listener perception was more accurate for lengthened compared to shortened productions and better for stops than flaps. However, listeners misperceived /d/ for /t/ when talkers lengthened their /d/ closures. Moreover, production changes talkers made following a misrecognition improved listener perception for medial /t/, but not medial /d/, which was at-chance. These findings indicate that talker adjustments made to remedy a misrecognition do not universally aid listeners’ perception.
The burden of face masks on speech in Parkinson's disease: Impact of clear and loud speech styles
Authors: Knowles Thea , Badh Gursharan
Published: May 2022

Face masks, now ubiquitous as a means of reducing COVID-19 transmission, have been shown to act as a low pass acoustic filter on speech. People with Parkinson’s disease (PwPD) and dysarthria may be especially vulnerable to the detrimental effects of masks, which may have negative consequences on spoken communication. The speech of PwPD has been shown to have lower concentrations of high frequency spectral energy and is perceptually characterized by a low speech volume and a breathy-hoarse voice quality. Increased vocal effort may aid in overcoming the filtering effects of masks. The purpose of this study was to quantify the effects of three masks (none, surgical, KN95) and three speech styles (habitual, clear, and loud) on the spectral characteristics of speech in PD. Fifteen PwPD and fifteen controls read aloud sentences with and without masks in three speech conditions. Measures of spectral tilt were taken from the long-term average spectra and modelled as a function of group, mask, and style. While both masks were associated with overall attenuation (steeper spectral tilt), a greater decrease was found for the PwPD (group by mask interaction). Loud speech, followed by clear speech, was effective in overcoming these effects for both groups.
Features analysis to label sound sources by long-term monitoring
Authors: De Salvio Domenico , Bianco Michael J. , Gerstoft Peter , D'Orazio Dario , Garai Massimo
Published: May 2022

Background noise, speech privacy, and productivity are strictly related in offices. Employees’ speech may affect the performance of colleagues disturbing their concentration. On the other hand, HVAC noise can mask irrelevant speech noise, improving in some way employee’s comfort. Thus, it becomes important to achieve the ability to individuate in an unattended way the different sound sources during working hours: mechanical (HVAC, devices, computers, …), human, traffic, activities in nearby spaces. Clustering techniques provide tools to find patterns among unlabeled data. In a previous study, Gaussian Mixture Model and K-means clustering were applied to sound level meter measurements carried out during working hours. The reliability of results encourages the investigation to find robust features to label the sound sources. In the present work, a sound level measurement has been carried out alongside the audio recording of the working activities throughout a whole day. Besides the clustering performed via Gaussian Mixture Model and K-means clustering over the sound pressure levels strings, a Variational Autoencoder was used to find latent features from the recording. Correlations between the methods explore the chance to obtain a broader understanding of data obtained by long-term monitoring.
Acquisition functions in Bayesian optimization of ocean acoustic waveguides using Gaussian processes
Authors: Jenkins William F. , Gerstoft Peter
Published: May 2022

Geoacoustic model optimization and inversion are computationally expensive endeavors. In cases where a parameter grid search is prohibitively expensive, optimization produces an approximated solution through sampling techniques such as Markov chain Monte Carlo, simulated annealing, and genetic algorithms. More recent work proposes replacing such sampling with a Bayesian approach that uses a Gaussian process as a surrogate model of the objective function. The surrogate model represents the posterior on the objective function and is updated with each sample evaluation. As an alternative to sampling methods listed above, acquisition functions incorporate the uncertainty in the posterior to select the next point to be sampled and can greatly speed the optimization. In this study, four common acquisition functions are described encompassing approaches that use manual tuning (upper confidence bound), improvement criteria (probability of improvement and expected improvement), and information criteria (entropy search). Results are presented from an acoustic parameter search for a shallow water waveguide for each function. Expected improvement is found to be the preferred acquisition function for the simulations, converging on the optimal solution more quickly than the other acquisition functions.
Statistical-based feature extraction and classification of active sonar data
Authors: Kubicek Bernice , Sen Gupta Ananya , Kirsteins Ivars
Published: May 2022

Sonar target recognition is difficult due to the potential nonlinear overlap within an acoustic color response due to various backscatter and clutter within the ocean. This talk presents initial results from using a statistical model of feature vectors in conjunction with machine learning classifiers. Canonical correlation analysis (CCA) seeks to find two linear combinations of data by maximizing the correlation between the linear combinations while maintaining unit variance. In this application, CCA is used as a feature extraction method before target classification of active sonar data experimentally collected during the Shallow Water Active Classification (SWAC)-1 and SWAC-2 sea trials in the Malta Channel. The database consists of 20 targets; three were analyzed using this method. The data are generated by taking windows of consecutive pings from the ping-vs-time domain and performing CCA. The intuition behind using CCA is that there are persistent features within the data that morph over time due to changing target aspect angles and platform positions which can be represented by the maximally correlated linear combinations of data among consecutive pings. The resulting linear combinations are feature vectors used to train a single hidden-layer neural network classifier. Results are reported as overall classification accuracy and confusion matrices.
Lessons learned that impact acoustics from the California Courts Program
Authors: Paoletti Dennis , Ham Clifford
Published: May 2022

Architect Clifford Ham served as the Project Director and Principal Architect for the Judicial Council of California Administrative Office of the Courts. He was responsible for overseeing more than 450 court facilities throughout California. Projects ranged from renovations and small single court buildings in remote locations to new multistory (31 and 71 multiple purpose courtrooms) in dense major urban areas. As an architect, with courtroom design experience, he was able to efficaciously support all aspects of design, engineering, and specialty consulting. Throughout the process, projects were implemented to effectively meet the needs of various stakeholders. California Trial Court Facilities Standards, covering all aspects of architectural design and engineering, had been developed when the program began in 2006, with minor revisions leading up to the new 2020 edition. Revisions gained from first-hand experience emphasized changes in the guiding principles and updated technical areas which influenced the design and cost of courthouses. This presentation will review the discuss significant aspects of the overall courts program with specific emphasis on acoustics. Case study examples will present some interesting subtleties in the planning and design process that should be realized to avoid costly follow-up repair solutions after occupancy.
Combined thermoacoustic cooling and ortho-para conversion of cryogenic hydrogen
Authors: Matveev Konstantin I. , Leachman Jacob I.
Published: May 2022

Hydrogen is a promising fuel for our future, as it can be produced with renewable energy sources and it does not emit harmful emissions when reacting with oxygen. To make the hydrogen economy viable, hydrogen needs to be transported as a dense cryogenic liquid. Since efficiencies of current cryocoolers are relatively low, improvements of the cooling technologies are required. In this study, an innovative solution involving thermoacoustic flow-through cooler is considered. Acoustic waves passing through porous medium can pump heat and cool hydrogen flowing through the system. An important feature of cryogenic hydrogen is the shift between its equilibrium ortho and para isomer fractions, which requires additional removal of heat. Since the natural conversion is slow, it must be augmented by catalysts for fast transition. The advantage of using the flow-through thermoacoustic system to cool hydrogen is that a catalyst can be placed in the porous matrix where hydrogen flows, so it can be cooled and undergo conversion at the same time. A mathematical model describing this process has been developed. Results showing achievable coefficients of performance, temperature drops, and flow rates of hydrogen are presented for both standing-wave and travelling-wave systems.
Acoustic streaming in the cochlea
Authors: Thompson Charles , Chandra Kavitha , Aoki Emi , Keefe Aidan
Published: May 2022

This presentation examines the fluid motion resulting from airborne and bone conduction excitation in the cochlea. The time-averaged velocity, termed acoustic streaming, driven by the gradient of the Reynolds stress, is of particular interest. The effect of asymmetry in the oval and the round window velocity and its influence pressure gradient across the cochlear partition and acoustic streaming is explored. It is shown that the streaming flow is a function of the reciprocal of the Strouhal, 1/S and the oscillatory Reynolds number, 1/R, have a magnitude much less than one for frequencies of interest. The work presented will focus on the parameter range R/S2 = O(1). The streaming velocity is obtained in terms of asymptotic expansion in terms of the reciprocal of the Strouhal number. Solution of the streaming flow outside the viscous region is obtained using boundary conditions derived from a matched asymptotic analysis.
Ultrasonic scattering in two-phase polycrystalline materials
Authors: Islam Showmic , Turner Joseph A.
Published: May 2022

Typically, many of the polycrystalline materials found in nature and those created using different manufacturing processes consist of multiple phases. Careful nondestructive characterization of these materials is of fundamental importance for quality assurance because microstructure is strongly correlated with mechanical performance. Ultrasonic scattering measurements have shown high sensitivity to material microstructure such that this approach is of interest for multi-phase materials. A fundamental understanding of scattering from idealized two-phase materials would provide essential information regarding the predictive nature of scattering measurements to quantify such microstructures. For this purpose, samples were created using spark plasma sintering (SPS) from mixtures with three different ratios (with respect to mass) of Cu and Fe powders. These elements do not alloy such that the resulting samples will not have any intermediate phases. Moreover, one pure Cu sample and one pure Fe sample were also sintered using SPS. The samples were imaged using electron backscatter diffraction (EBSD) to quantify the material organization. Ultrasonic backscatter and attenuation measurements were performed on the samples and the results were used for comparison with scattering models. Prospects for nondestructive evaluation of such materials are also discussed. [Work supported by Air Force Research Laboratory (AFRL) under prime contract FA8650-15-D-5231.]
Anisotropy of elastic and photoelastic properties of lithium niobate crystals
Authors: Akhmedzhanov Farkhad , Abdirakhmonov Ulugbek
Published: May 2022

The elastic and photoelastic constants of lithium niobate crystals and the attenuation coefficients of acoustic waves at room temperature have been determined by the Bragg diffraction of light by sound. The components of the photoelasticity tensor were determined by the modified Dixon method. The obtained values of the constants were used to determine the anisotropy of the effective elastic and photoelastic constants with a change in the direction of propagation of acoustic waves in the (100) symmetry plane, for different directions of the wave vector and polarization of light relative to the sound wave vector. It is shown that, for certain geometries of the Bragg light diffraction, there is a correlation between the orientation dependences of the effective elastic and photoelastic constants in the investigated plane. The results of the study can be used to analyze the anisotropy of the photoelastic properties of lithium niobate crystals and determine the diffraction geometry with the highest efficiency of Bragg light diffraction.
Multimodal training using pitch gesture improves Mandarin tone recognition for children with cochlear implant
Authors: Ding Hongwei , Zhang Jing , Zhang Hao , Zhang Yang
Published: May 2022

Prelinguallydeafened Mandarin-speaking children with cochlear implants (CI) encounter a significant challenge in perceiving lexical tones accurately due to their limited language experience and insufficient pitch information provided by CI devices. To facilitate their tonal perception, we examined the role of pitch gestures in the training program, which was reported to be beneficial in acquiring Mandarin lexical tones for foreign learners of Chinese. In the current study, 18 prelingually deafened preschoolers with CI were recruited in Shanghai. They were randomly assigned to two groups. The experimental group was trained with audio and pitch gestures, and the control group was trained with audio only. Three tone-identification tests were conducted before, in the middle, and after the eight training sessions. Although the two groups had identical performance before the training, the experimental group demonstrated significantly better performance than the control group after training sessions, especially in noise conditions. The results thus showed that multimodal training with pitch gestures improved the tone recognition ability of CI children more than sheer auditory training. Our findings offer more evidence to support that learning to perceive lexical tones can be facilitated by multimodal cues and also provide important implications for optimizing rehabilitation training after implantation.
Implicit learning versus explicit instruction in morphophonological learning
Authors: Drake Shiloh , Preligera Isabel , Baese-Berk Melissa M.
Published: May 2022

This study uses an artificial grammar learning task to probe the learning of abstract morphophonological structure. Two sets of nonce words were created, one with plural forms using concatenative morphology (similar to English) and the other using non-concatenative morphology (similar to Arabic). Both sets had multiple phonologically conditioned allomorphs. Half of the participants were provided with instruction and feedback, and half were not. These results show that even minimal instruction and feedback leads to learning abstract morphological structure through the use of nonce words. While instruction and feedback at this level may not make non-concatenative morphology more straightforward to English speakers, their subconscious understanding of the morphophonological system is improved and leads to higher quality guesses on the derivations of the nonce words than on previous work with implicit learning of non-concatenative morphology alone (e.g., Drake, 2018). Feedback provides negative input for a second-language learner to narrow possibilities when following an otherwise abstract morphophonological pattern, particularly in a morphophonological system unlike that employed by their primary language.
Children’s perception of accent distance for native and nonnative varieties
Authors: Henry Malachi , Bent Tessa , Holt Rachael F.
Published: May 2022

Adults are sensitive to the presence and strength of accents different from their own. Children also are sensitive to the presence of unfamiliar accents, but much less is known about their awareness of accent strength. To address this gap, this study used a ladder task, in which listeners rank talkers based on their perceived distance from the home standard. Female adult talkers representing four native, six nonnative, and one bilingual English accents were included. Six-year-olds, 12-year-olds, and adults completed two ladders in which all talkers produced the same sentence and one ladder with a unique sentence for each talker. Average rankings were significantly correlated across age groups, with greater agreement for consistent than unique sentence ladders. Strategies used by six-year-olds differed from older children and adults. The youngest children arranged talkers into two or three distinct groups with more horizontal groupings while older children and adults primarily arranged talkers in a vertical array. These results support previous findings that young children distinguish their own accent from unfamiliar accents. Furthermore, the study provides new data demonstrating that sensitivity to accent distance emerges in the early school-aged years with continued maturation during middle childhood. [Work by NSF grants 1941691 and 1941662.]
Neural correlates of speech in noise perception differences between combined electric-acoustic stimulation and standard cochlear implants
Authors: Hong Jean , Shim Hwan , Kim Subong , Hansen Marlan , Gantz Bruce , Choi Inyong
Published: May 2022

Cochlear implants have evolved to utilize residual acoustic hearing that combines to electric stimulation, known as electric-acoustic stimulation (EAS). However, there are mixed expectations about the benefits of EAS. A positive perspective expects that contributions from residual hearing provide better access to acoustic cues that is helpful for speech-in-noise perception. An opposing view concerns potentially poorer spectral resolution of EAS electrodes’ stimulation as those electrodes are often inserted close to lateral wall, which may cause poorer speech-in-noise perception. This study aimed to directly compare neural processes of speech-in-noise perception between EAS and standard CI users to provide an answer to the above alternative expectations. We used 64-channel EEG to measure cortical evoked responses to (1) background noise and (2) target word while listeners perform a word-in-noise task. Then, we compared the amplitude ratio of evoked responses to the target word and background noise, referred to as “internal SNR,” which reflects how well target sound is unmasked from the mixture of speech and noise. Based on the comparison of 55 EAS and 22 standard CI users, internal SNR was significantly larger in EAS CI users. This result indicates that EAS provides enhanced neural processes for speech unmasking.
Perception advantages of foreign directed speech
Authors: Wheeler Rebecca
Published: May 2022

Foreign directed speech (FDS) is a listener directed speech style used when native speakers interact with non-native listeners of a language. This study considers if native and non-native listeners benefit from the phonetic features of FDS in English. 43 native English speakers and non-native speakers were recruited on Amazon Mechanical Turk. Participants were presented with an audio clip and two pictures. They were asked to click on the correct image based on the audio given with reaction times recorded. Each participant was given a randomized order of speech tokens: 12 tokens from the two speech conditions, native speech (NS) and FDS. The data showed that speech condition had a significant effect on reaction time, where FDS yielded faster reaction times than native speech (est = −0.024, t = 2.035, p = 0.04). Listener language background did not have a significant effect, with both groups performing similarly in reaction times across both speech conditions. The results of this study show that the phonetic features of FDS are beneficial for comprehension when compared to native speech regardless of listener language background. This may be because the phonetic features of FDS are similar to the characteristics of other listener directed speech styles.
Vocal emotion recognition by native Turkish children with normal hearing and with hearing aids
Authors: Babaoğlu Gizem , Yazgan Başak , Erturk Pınar , Gaudrain Etienne , Rachman Laura , Nagels Leanne , Launer Stefan , Singh Gurjit , Chatterjee Monita , Yücel Esra , Sennaroğlu Gonca , Başkent Deniz
Published: May 2022

Development of vocal emotion recognition in children with normal hearing takes many years before reaching adult-like levels. In children with hearing loss, decreased audibility and potential loss of sensitivity to relevant acoustic cues may additionally affect vocal emotion perception. Hearing aids (HAs) are traditionally optimized for speech understanding, and it is not clear how children with HAs are performing in perceiving vocal emotions. In this study, we investigated vocal emotion recognition in native Turkish normal hearing children (NHC, age range: 5–18 years), normal hearing adults (NHA, age range: 18–45 years), and children with HAs (HAC, age range: 5–18 years), using pseudo-speech sentences expressed in one of the three emotions, happy, sad, or angry (Geneva Multimodal Emotion Portrayal (GEMEP) Corpus by Banziger and Scherer, 2010; EmoHI Test by Nagels et al., 2021). Visual inspection of the preliminary data suggests that performance increases with increasing age for NHC and that in general, HAC have lower recognition scores compared to NHC. Further analyses will be presented, along with acoustical analysis of the stimuli and an exploration of effects of HA settings. In addition, for cross-language comparison, these data will be compared to previously collected data with the same paradigm in children from the UK and the Netherlands.
Visual and acoustic influences on linguistic discrimination during interviews
Authors: Siren Kathleen
Published: May 2022

This study investigates the influence of bias during the interview process. University students of different races and ethnicities recorded pre-determined responses to questions that might be asked during a graduate admissions interview. These recorded responses were played for a group of university professors and a group of non-academicians. The listeners heard student responses under three conditions: (1) audio only, (2) audio paired with a matched picture of the student, and (3) audio paired with a picture of a student of a different race and ethnicity. Listeners rated responses along several continua, including knowledge of field, competency, and motivation. Student responses were compared across several acoustic features including fundamental frequency, pitch range, and rate. Results are discussed in terms of potential linguistic discrimination that may be exacerbated during face-to-face graduate admissions interviews and acoustic characteristics of speech that may influence perceptual bias based on race.