bluuebunny/crossref_metadata_2025 huggingface dataset:
Can a trained deep neural network be implemented into hearing technology?
Authors: Healy Eric , Delfarah Masood , Vasko Jordan , Carter Brittney , Wang DeLiang
Published: June 2017

Recent work has shown that a machine learning algorithm can produce large speech intelligibility in noise increases for hearing-impaired listeners. This algorithm involves a deep neural network trained through supervised learning to estimate the ideal binary or ratio mask. The direct translational potential of this work is addressed currently. Primary issues surrounding future implementation into hearing aids and cochlear implants involve (i) the ability to generalize to conditions not encountered during training, and (ii) the computational load associated with operation of such an algorithm. Substantial advances have been made with regard to generalization. These will be outlined as will associated decisions that can be made. The computational load associated with training and operation of a network will also be addressed. Here, we propose an alternative implementation that offers multiple advantages over current approaches.
Effects of high-frequency hearing loss on the unmasking produced by narrowband maskers
Authors: He Yuan , Lentz Jennifer
Published: June 2017

To examine whether high-frequency hearing loss impacts the unmasking abilities of the ear, we measured the unmasking effects with narrowband maskers in different frequency regions at a suprathreshold level. Listeners with normal-hearing and those with mild hearing loss in extended-high-frequency regions (12-20 kHz) participated in this study. Unmasking effects were evaluated using a method based on two-tone unmasking (Shannon, 1976). But rather than tones, narrowband noises were used as the maskers. Preliminary results suggest that unmasking effects can be successfully observed using narrowband maskers. Furthermore, we will evaluate effects of masker frequency and bandwidth and the relationship between extended-high-frequency hearing loss and unmasking effects. The possibility of using unmasking effects to assess hidden hearing loss as a frequency-specific measurement will be discussed.
Are reports of temporary threshold shift-like symptoms by humans with normal hearing associated with hidden hearing loss?
Authors: Brammer Anthony J. , Yu Gongqiang , Grady James J. , Parham Kourosh , Cherniack Martin G. , Wannagot Shannon , Cienkowski Kathleen M.
Published: June 2017

Forty-six subjects with normal hearing, mean age 20.2 years, were selected from 451 volunteers completing a questionnaire concerning hearing, exposure to noise, experiencing TTS-like symptoms, and speech understanding. Metrics quantifying reports of TTS-like symptoms were constructed from responses to questions concerning hearing immediately after noise exposure. Statistically significant deteriorations in scores on the Speech, Spatial and Qualities of Hearing Scale (SSQ) (Gatehouse & Noble, Int J Audiol 43, 85-99 (2004)) were found with increasing values of TTS metrics for all SSQ questions. Groups reporting TTS-like symptoms (“exposed”), and “controls” (with little / no noise exposure and no reports of TTS-like symptoms), were formed from the subject pool with mean hearing levels differing <2 dB from 250Hz—8kHz. There was no difference in mean word scores between groups in a Modified Rhyme test conducted in speech-spectrum shaped noise. However, the exposed group exhibited a statistically significant deterioration in threshold for detecting 4Hz amplitude modulation of a 500Hz carrier at 10 dB sensation level (SL) compared to controls, and an improvement at 50 dB SL. It thus appears that TTS-like symptoms reported by persons with normal hearing may be associated with subtle suprathreshold changes in auditory performance. [Work supported by NIOSH.]
Effect of a mixed rate cochlear implant strategy on speech understanding
Authors: Leclère Thibaud , Kan Alan , Litovsky Ruth
Published: June 2017

Bilateral cochlear implant (BiCI) users perform better on speech understanding in noise with two vs. one implants, however, they still perform significantly worse than normal hearing (NH) listeners. CI processors encode speech envelopes using pulsatile stimulation at a relatively high rates, delivered to all electrodes. At these rates, slow-varying temporal fine structure of the original signal is lost and interaural time difference (ITD) cues are unavailable. To maintain relatively good performance on both speech recognition and localization, we hypothesized that high- and low-rate pulses could be mixed in a single stimulation strategy, and presented to different channels. As a first step, NH listeners were tested on speech recognition in noise. Pulsatile excited vocoders, with center frequencies varying from 4000 to 8417 Hz, and envelope modulation at high (1000 Hz) or low (100 Hz) rates were used to simulate multi-channel CI processing. Comparisons were made for conditions in which some high-rate channels are replaced with low-rate channels intended to ultimately preserve ITD sensitivity. Results from this experiment are important for determining the feasibility of using mixed-rate CI stimulation strategies in healthy auditory systems, and determining the extent to which speech recognition is robust to the insertion of low-rate channels.
The relationship between electrical auditory middle-latency response components and measures of auditory performance and speech intelligibility in pediatric cochlear implant recipients
Authors: Deshpande Shruti B. , Lu Zhaoyi , Pan Tao , Ma Furong
Published: June 2017

Evidence for the utility of electrically-evoked auditory responses, as measures of objective hearing assessments in pediatric cochlear implant (CI) recipients, is proliferating. Recently, we demonstrated the relationship between electrical auditory brainstem response (EABR) and measures of auditory performance and speech intelligibility in pediatric CI users (Wang, Pan, Deshpande, & Ma, 2015). However, the EABR reflects activity only up to the auditory brainstem. The electrical auditory middle-latency response (EAMLR) is sensitive to the functioning of the sub-cortical structures as well as the auditory cortex and thus has greater utility in predicting auditory perception and processing. Here, we present data from 40 pre-lingually hearing impaired, pediatric CI recipients. The relationship between components of the EAMLR (latencies of Na, Pa, Nb, Pb; Na-Pa amplitude; and Na-Pa interval) and measures of auditory performance and speech intelligibility assessed using care-giver rating scales such as Categories of Auditory Performance (CAP) (Archbold, Lutman, & Marshall, 1995) and Speech Intelligibility Rating (SIR) (Allen, Nikolopoulos, Dyar, & O'Donoghue, 2001), respectively, are analyzed. EAMLR profiles of “good” versus “poor” CI users (based on CAP and SIR ratings) will be discussed. Additionally, the effect of age of implantation on the EAMLR, CAP and SIR outcomes will be considered.
Non-sensory biases in a pitch-discrimination task for bilateral and single-sided deafness cochlear-implant listeners
Authors: Stakhovskaya Olga , Bernstein Joshua G. , Goupell Matthew
Published: June 2017

Matching the interaural place of stimulation is likely to improve binaural processing for bilateral (BI) and single-sided deafness (SSD) cochlear-implant (CI) listeners. Although pitch matching can be used to estimate interaural mismatch for these listeners, non-sensory biases (e.g., responding to the test-frequency range rather than interaural pitch comparisons) could influence the accuracy of place-match estimates. This study evaluated pitch discrimination as a method of estimating the relative interaural places of stimulation for individual CI electrodes for BI-CI and SSD-CI listeners. Three different frequency ranges, and randomization of the stimulus presentation across reference electrodes, were used to measure non-sensory biases. Results showed substantial frequency-range effects for the majority of reference electrodes tested for both listener groups, shifting place-match estimates by as much as about 7 mm for some listeners. Reference-electrode randomization affected a smaller proportion of the estimates, producing shifts of 2-3 mm or less. These findings suggest that pitch discrimination might not reliably estimate relative interaural place of stimulation for BI-CI and SSD-CI listeners. [The views expressed in this article are those of the authors and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. Government. Funding: NIH-NIDCD R01-DC-015798 (Goupell/Bernstein).]
Voice gender release from masking in cochlear implant users is correlated with binaural pitch fusion
Authors: Oh Yonghee , Reiss Lina , Srinivasan Nirmal , Jakien Kasey , Diedesch Anna , Gallun Frederick J. , Hartling Curtis
Published: June 2017

Spatial and voice gender separation of target from masking speech leads to substantial release from masking in normal-hearing listeners. However, binaural pitch fusion is often broad in cochlear implant (CI) listeners, such that dichotic stimuli with pitches differing by up to 3-4 octaves are fused (Reiss et al., 2014). We hypothesized that broad binaural fusion could reduce a listener’s ability to separate competing speech streams with different voice pitches, and thus reduce the voice gender as well as spatial benefit for speech perception in noise. Speech reception thresholds were measured in both bilateral and bimodal CI users, using male and female target talkers at two spatial configurations (co-location and 60-degrees of target-masker separation). Binaural pitch fusion was also measured. Different-gender maskers improved target detection performance in bimodal CI users, and performance was better with female than male targets in bilateral CI users. No spatial benefit was seen in either CI group. As hypothesized, voice gender masking release was strongly correlated with binaural fusion range in bimodal CI users. These results suggest that sharp binaural fusion is necessary for maximal speech perception in noise in bimodal CI users, but does not benefit bilateral CI users. [Work supported by NIH-NIDCD grant R01 DC01337.]
The role of spectral and temporal cues for vocal emotion recognition by cochlear implant simulations
Authors: Zhu Zhi , Miyauchi Ryota , Araki Yukiko , Unoki Masashi
Published: June 2017

It has been known that cochlear implant (CI) listeners have difficulty in vocal emotion perception. Researches on vocal emotion perception of CI listeners have been studying ways to simulate responses of CI listeners by using noise-vocoded speech (NVS) as CI simulations with normal-hearing listeners. The purpose of this study is to clarify the relative contributions of spectral and temporal cues in vocal emotion recognition for NVS. In the simulation, the spectral cue can be numbers of speech processing channels are 4, 8, and 16. The cutoff frequency of the envelope filters ranged from 0 to 64 Hz. Sentences were produced by one female talker according to five target emotions: neutral, joy, cold anger, sadness, and hot anger. As a result, the recognition rates significantly improved as the cutoff frequency was increased for all emotions. Moreover, the number of channels only effect the recognition rate of neutral, joy, and cold anger. The results suggest that temporal cues contribute to vocal emotion recognition. However, the contribution of spectral cues on vocal emotion recognition will be depended on the type of emotion. In the future, the relationship between modulation spectral features and these perceptual data will be discussed.
Theoretical evidence for lack of correspondence between spectral ripple parameters and output of the cochlear implant processor, and an alternate explanation for the correlation with speech perception scores
Authors: O'Brien Gabrielle , Winn Matthew
Published: June 2017

The spectral ripple test is a popular measure of spectral resolution that, in cochlear implant (CI) listeners, has been shown to correlate with speech recognition scores. In the test, listeners distinguish between sounds whose broadband spectra contain some variable number of peaks (i.e. spectral density), with some spectral modulation depth. A meta-analysis of literature on spectral ripple tests in CI listeners shows a generally consistent ceiling level of performance around 2 ripples per octave, with some outliers performing above. We propose that there is a critical point in spectral density at which the output of the CI transitions from representing spectral ripples to a qualitatively different signal, resulting from the interaction between the spectral peaks and the number of active device channels. Artefactual nonlinearities for ripples of higher densities generally do not resemble ripples but may accidentally match the spectral envelope characteristics of speech sounds. The unintended correspondence between the test signal and speech at high densities, rather than a true metric of spectral resolution, might explain the predictive power of the test. Regardless of predictive power, our results suggest that ripples exceeding a critical spectral density cannot be defined along the same continuum as ripples below that value.
Effects of the interaction between the pitch of band noise and color on psychological evaluation
Authors: Konno Ryosuke , Akita Takeshi
Published: June 2017

In the present research, we are studying about the effects of complex stimuli of visual and auditory on perception and cognition. Based on the above way of thinking, in this time, we made an psychological experiment about the interaction between “the pitch of a band noise” and “color.” In the experiment, we made subjects look into the room model. In the model, visual stimulating are presented by color scheme cards. And also, auditory stimulating of different stimulations in which visual stimulation of color scheme cards and auditory stimulation of 1/3 octave band noises (100 Hz, 1 kHz, and 10 kHz) are presented to subjects through loud speaker. After the one trial of visual and auditory stimulation, we heled quetionnaire about the impressions. As a result, we could obtain that subjects evaluated the bright and light impression lower when the bright color is presented with 100 Hz band noise. However, its evaluated value is higher than the obtained when only the 100 Hz noise is presented to subjects. It seems that a person composes the impressions by means of combined sensation of visual and auditory information.
A pitch model based on rate, place, and envelope information
Authors: Dahlbom David A. , Braasch Jonas
Published: June 2017

A functional model of the auditory processing of pitch is presented. The model draws on Licklider's duplex theory of pitch [Experientia, 7, 128-143] and further extends his approach by adding an envelope processing stage. The incoming signal is sent through a gammatone filter bank to simulate the behavior of the basilar membrane. Within each auditory band the autocorrelation function is calculated and a pitch estimate is made based on the delay between the main peak and the adjacent side peak. A weighting for the salience of each pitch cue is then calculated based on the place theory using the distance of the estimated fundamental frequency from the band's center frequency. Finally, the envelope is determined for each band and an additional pitch estimate is made based on the autocorrelation function of the envelope. These three calculations—which provide rate, place, and envelope information—are combined into a global pitch estimate, explaining the pitch percept associated with a wide range of stimuli. The model can be easily integrated into larger auditory processing frameworks in which envelope information is important (e.g., monaural source segregation and binaural localization). [Work supported by NSF BCS-1539276.]
Speech transformed into song heightens temporal sensitivity but weakens absolute pitch sensitivity
Authors: Graber Emily , Simchy-Gross Rhimmon , Margulis Elizabeth H.
Published: June 2017

The speech-to-song illusion (STS) is a phenomenon in which some spoken utterances perceptually transform to song via repetition. The existence of utterances that do and do not transform makes it possible to investigate similarities and differences between the musical and linguistic modes of listening, with the former elicited by transforming utterances and the latter by non-transforming utterances. In Experiment 1, inter-stimulus interval durations within STS trials were either steady, slightly variable, or highly variable. Participants reported how temporally regular the utterance entrances were. In Experiment 2, participants were first exposed to STS trials and then asked to choose the transposition of the utterances they heard during the exposure phase. Results indicate that listeners exhibit heightened awareness of temporal manipulations to transforming utterances compared to non-transforming utterances, but not to absolute pitch manipulations. This suggests that compared to the linguistic mode of perception, the musical mode entails an increased sensitivity to temporal regularity, but not to absolute pitch. The methodology used here establishes a framework for implicitly differentiating musical from linguistic perception, as well as for behaviorally investigating the different cognitive apparatus that people use when activating the musical or linguistic mode of perception.
The effect of musicality on cue selection in pitch perception
Authors: Kuang Jianjing
Published: June 2017

Our previous experiments (Kuang and Liberman 2015, 2016) have shown that spectral cues have significant effects on pitch perception. One striking finding from Kuang et al. (2015) is that there is a great deal of cognitive variation among individuals: musicians are much less affected by the spectral conditions; by contrast, non-musicians heavily rely on spectral cues in pitch perception. We hypothesized that this is because musicians are more sensitive to fine f0 difference. Extending from this finding, our present study examines whether the degree of musicality of a given speaker have effects on his/her strategies of perceiving pitch. The current experiment consists of two parts: musicality tests and pitch classification test (as in Kuang and Liberman 2016). It is found that the people with higher musicality scores tend to more heavily attend to f0 cues than the people with much lower musicality scores do. This result supports our hypothesis, and has important implications for tone acquisition.
Differences in sound perception are reflected by individual auditory fingerprints in musicians
Authors: Benner Jan , Reinhardt Julia , Hofmann Elke , Stippich Christoph , Schneider Peter , Blatow Maria , Davies William J.
Published: June 2017

Musicians have been reported to show significant inter-Individual differences in elementary hearing functions, sound perception mode, musical instrument preference, performance style, as well as more complex musical abilities like absolute- and relative pitch perception, and auditory imagery. However, it remains unexplored how individual elementary hearing functions and corresponding musical abilities are inter-connected and to what extend they reflect individual differences in the musical behavior of musicians. Using a combination of five listening tests and assessing resulting psychoacoustic parameters, we were able to determine individual auditory fingerprints on the single subject- and group level. 93 musicians (49 professionals and 44 amateurs) were individually tested for: frequency discrimination threshold, holistic and spectral sound perception, absolute pitch perception, relative pitch perception (musical interval recognition), and musical imagery (AMMA). On the individual level, our results show that auditory fingerprints differ remarkably between subjects. On the group level, using PCA and cluster analysis, we found four main components represented significantly different in the three characteristic clusters of subjects. Taken together, our findings suggest that inter-individual differences in the auditory fingerprint reflect the high variability of individual sound perception and may have crucial impact on specific musical preference, style and performance of musicians.
Pitch-trained neural networks replicate properties of human pitch perception
Authors: Gonzalez Ray , McDermott Josh
Published: June 2017

Pitch perception exhibits well-established dependencies on stimulus characteristics. In human listeners, pitch is predominantly determined by low-numbered harmonics that are believed to be resolved by the cochlea, but is also conveyed to a lesser extent by high-numbered harmonics that are not individually resolved. Moreover, the relative phases of harmonics influence pitch perception only when the stimulus consists of high-numbered (unresolved) harmonics. To assess whether these dependencies reflect information constraints on the problem of extracting pitch from peripheral auditory representations, we trained a convolutional neural network to estimate the fundamental frequency (F0) of tones in noise. The tones replicated basic spectral properties of natural sounds. The resulting neural network model was tested on complex tones that varied in harmonic composition and phase (as in classic psychoacoustic experiments). The network qualitatively replicated features of human pitch perception, including better performance for tones containing low-numbered harmonics and worse performance when the phases of high-numbered (presumably unresolved) harmonics were randomized. The results are consistent with the notion that human pitch perception exhibits near-optimal performance characteristics for the task of estimating F0 from peripheral auditory representations, in that optimizing for performance of this task is sufficient to reproduce human performance characteristics.
Aging and the use of syntactic and talker consistency cues in a temporally interleaved task
Authors: Helfer Karen S. , Poissant Sarah , Merchant Gabrielle R.
Published: June 2017

The purpose of the present study was to identify differences between older and younger listeners in how they use talker consistency and word order cues in both to-be-attended and to-be-ignored streams. A temporally-interleaved method was used in which participants were asked to report the first and then every other word within a stream of sounds, and ignore the intervening sounds. The to-be-attended words were presented in either correct syntactic order (“Anne dropped three old mats”) or in random order (“Six pink Dave zones lost”). The to-be-ignored sounds were either words (in syntactically-correct or random order), steady-state noise, or environmental sounds. When stimuli were words, the talker was either consistent or varied for all five words of the target and/or masker. Preliminary analyses showed that listeners in both groups were only minimally affected by intervening stimuli that were samples of noise or environmental sounds. When the interleaved sounds were words, younger adults were able to take greater advantage of syntactic correctness of the to-be-attended stream, as compared to older adults. Both younger and older participants benefitted from a consistent target talker when syntactic cues were unavailable. [Work supported by NIDCD R01 DC012057).]
Three-dimensional ultrasound images of Polish high front vowels
Authors: Lulich Steven M. , Cavar Malgorzata E. , Nelson Max
Published: June 2017

The 3-D ultrasound method has been applied to collect data on Polish high front vowels. In particular, Polish has one unambiguous high front vowel and another one that in the phonological literature is variously referred to as high central or back unrounded and transcribed as [ɨ]. While there exists a sizeable body of articulatory research on Polish, including X-rays from as early as the 50s and 60s, the ultrasound data reveal more detail about the position of the tongue center and tongue root. The data evaluated so far support the view that the vowel transcribed as [ɨ] is a front vowel. The two front vowels differ in the position of the tongue root, relative raising of the tongue, and extent of lip gesture, but do not differ substantially with regard to tongue body advancement on the font-back axis. The data also capture the temporal aspect of speech, and together with time-aligned audio recordings and video recordings of the lips, allow for fine-grained analysis of the acoustic effects of these articulatory gestures.
Allophonic variation of Polish vowels in the context of prepalatal consonants
Authors: Cavar Malgorzata E. , Lulich Steven M. , Nelson Max
Published: June 2017

Phonetic studies of Polish mention allophonic variation in Polish vowels, in that there is a systematic effect of the prepalatal consonant context. In particular, [u] is fronted, [ɛ] is raised, [a] is fronted and sometimes raised, and [ɔ] is fronted following a prepalatal consonant. Additionally, phonemic [i] is excluded after non-palatalized consonants, and the phonemic [ɨ] does not occur after prepalatals. Although X-ray data for Polish speech production exists from the 50s and 60s, no X-ray images are available of the contextual variants of vowels adjacent to prepalatal consonants. In this study, we present 3-D tongue shapes of the vowels in neutral and prepalatal contexts. The data show a combination of raising and fronting of the tongue body for all front vowels, and also a consistent effect of tongue root advancement.
Preschool children’s fast mapping of novel words in the presence of speech competitors
Authors: Grieco-Calub Tina M. , Fang Tiffany W. , Simeon Katherine M.
Published: June 2017

Children frequently learn new vocabulary in the presence of competing sounds. This study was designed to test the influence of speech competitors on children’s ability to learn novel label-object pairs. Preschool-aged children (N = 16) performed a fast-mapping task in both quiet (target speech = 60 dBSPL) and speech competitor conditions (58 dBSPL). In each condition, children were familiarized to three novel label-object pairs on a computer screen. Children were subsequently tested on whether they mapped each pair with a closed-set, three-alternative-forced-choice test: children pointed to the object that corresponded to the spoken label. On average, children learned equally well in each condition. Further inspection of individual data, however, showed a subset of children acquiring more label-object pairs in the competitor condition. The subject pool was split into two subgroups of children, those who performed > 5% better or worse in the competitor condition. Independent t-tests showed that children who performed better in the competitor condition had lower scores on an executive function test. Though counterintuitive, results suggest that children with poorer inhibitory control of irrelevant stimuli are better at fast mapping novel label-object pairs in the presence of acoustic competition. Cognitive demands associated with the fast-mapping task will be discussed.
Comparing musicians’ and non-musicians’ ability to make use of F0 differences between competing talkers in natural and monotone speech
Authors: Madsen Sara M. , Oxenham Andrew J.
Published: June 2017

Recent studies disagree on whether musicians have an advantage over non-musicians in understanding speech in noise. This study tested the hypothesis that better fundamental-frequency (F0) discrimination enables musicians to make better use of F0 differences between competing talkers. Sentence intelligibility was measured in a background of noise or two competing talkers, where the target and background speech were natural or monotonized. Participants were also tested with the Vocabulary and Matrix Reasoning subtests of the Wechsler Abbreviated Scale of Intelligence. As expected, speech intelligibility improved with increasing F0 difference between the target and the two maskers for both natural and monotone speech. However, no significant intelligibility advantage in speech was observed for musicians over non-musicians in any condition. F0 discrimination was significantly better for musicians than for non-musicians. Scores in the IQ test did not differ significantly between groups. Overall, the results do not support the hypothesis that musical training leads to improved speech intelligibility in speech or noise backgrounds. [Work supported by NIH grant R01DC005216, the Carlsberg, Augustinus, P.A. Fisker, and Knud Højgaard Foundations.]
Effects of wide dynamic range compression on speech signals with respect to reverberation
Authors: Giurda Ruksana , Georganti Eleftheria , Hassager Henrik G. , Dau Torsten
Published: June 2017

The sound perception in enclosed spaces is dominated by the room acoustics properties of the enclosures. Today, it is known that reverberation generated by walls and obstacles challenges hearing-impaired people, even with hearing aids, and several studies have been conducted to address this problem. However, relatively little is known about how various signal processing blocks (i.e., beamforming, wide dynamic range compression) within hearing aids affect the reverberation content of the speech signals. Aim of this work was to investigate and quantify the effects of wide dynamic range compression on the reverberant component of speech signals employing both subjective and objective methods. Several objective metrics which correlate with reverberation were applied on the speech signals before and after the compression. Moreover, a listening test with 14 normal hearing participants was performed to assess whether the changes in the reverberation content of the compressed signals were perceivable. The perceptual results show that the gain model changed the perception of reverberation of the speech signals tested. Finally, the correlation between the objective metrics and the perceptual results of the listening test was then investigated, indicating increased reverberation content for the compressed signals.
Perception of keywords elicited under various adverse acoustic environments
Authors: Iyer Nandini , Thompson Eric R. , Ennis Zachariah N. , Willis Abigail , Simpson Brian
Published: June 2017

In a recent study, keywords were elicited in spontaneous speech samples from eight pairs of interlocutors who completed the “spot-the-difference” Diapix task in one of three acoustic environments: quiet, 2-talker babble, or 8-talker babble. In some conditions, talkers were in the same acoustic environment and in others they were in disparate environments. In all cases, the acoustic environments were presented over headphones in order to obtain clean recordings of the speech but maintain the influence of the environment on production. The current study investigated the perception of the keywords in each of the three acoustic environments at different signal-to-noise ratios, when they were presented in either the same or disparate adverse environment than ones in which they were elicited. Results from the current experiment will be discussed with regard to intelligibility obtained when words were presented in the same vs. different environments; the differences obtained in perception might indicate whether speech modifications in adverse environments are specific to a particular environment or more global in nature. The correlations between perception results to acoustic measures of these keywords in these various acoustic environment will also identify key factors that might improve communication effectiveness in adverse environments.
Sensitivity to interaural timing differences using the advanced combinational encoder strategy
Authors: Kan Alan , Litovsky Ruth , Smith Zachary M.
Published: June 2017

When listening through clinical processors, sound localization in bilateral cochlear implant (BiCI) users is highly variable, and some patients perform rather poorly. While this is often ascribed to lack of access to temporal fine-structure interaural timing differences (ITDs), the potential role of envelope ITDs is often disregarded. Furthermore, sensitivity to ITDs alone has not been closely examined with the commonly used Advanced Combinational Encoder (ACE) strategy. In theory, envelope ITDs could be encoded with ACE and some BiCI users may be sensitive to this cue to locate sounds, which may explain why some BiCI users have better localization performance. ITD just noticeable differences (JNDs) were measured in 9 participants, using a novel setup of presenting whole-waveform-delayed words through the auxillary port of clinical processors. Listening with ACE, ITD JNDs ranged from 105-680 µs (unmeasurable in one listener). Localization root-mean-squared error ranged from 19-68 degrees. However, ITD sensitivity and sound localization were not significantly correlated (ρ = 0.5, p = 0.17). The unexplained range of sound localization performance in BiCI users is likely due to distorted and inconsistent binaural cues that arise from uncoordinated device programming and signal processing across the two ears. [Work supported by NIH-NIDCD (R03DC015321 to AK and R01DC003083 to RYL) and NIH-NICHD (P30HD03352 to Waisman Center).]
Psychoacoustics in the pre-electronic, electronic, and early digital eras
Authors: Levitt Harry
Published: June 2017

The history of psychoacoustics can be subdivided into three eras, Pre-electronic, Electronic, and Digital. We are currently in the middle of the Digital era. Psychoacousticians displayed remarkable ingenuity in furthering our understanding of auditory perception using the limited technology of the day. The brilliant use of spinning discs, innovative pulse generators, tuning forks provided fascinating new insights into the nature of hearing. The Electronic era began with the invention of the electronic amplifier. The high gain provided by electronic amplifiers opened the door to new areas of investigation. Fundamental new findings regarding non-linear distortion and protective auditory mechanisms resulted as well as the emergence of the field of audiology. Psychoacoustic research during the Electronic era focused more on the spectral properties of hearing, presumably because of the greater difficulty in manipulating pulsate stimuli. The invention of the digital computer provided the means for generating, analyzing and manipulating pulsate stimuli with the same degree of ease as spectral stimuli. The early Digital era thus resulted in major new findings relating to both the temporal and spectral properties of hearing. More importantly, it changed our thinking with respect to the measurement of hearing.
History of speech perception psycho-physics
Authors: Allen Jont B.
Published: June 2017

The history of speech psycho-physics is relatively recent, due to the complexity of quantifying information measures. All of this research required the invention of the Telephone (Bell, 1874). The first research was by Lord Rayleigh (1908), who used an Acousticon LT commercial PA system (c1905), followed by George Campbell (1910), who introduced the confusion matrix. In 1921 Harvey Fletcher took thousands of hours and dozens of different types of experimental data, resulting in the Articulation Index. Fletcher retired in 1950, and the speech work at Bell labs, lead by James Flanagan, switched to vocoder research. Work at Haskins began about the same time, with Liberman, Cooper and colleagues. Their main research questions was perceptual speech cues. There were more theories than facts. George Miller (1955) used Shannon's Theory of Information (1947) as the inspiration for experiments on speech information transferred. Between 1994-2005 the author repeated the work of Fletcher and Miller, using “modern computer methods,” and came to some new conclusions. Online demos will be presented, that reveal the consonant speech cues. These demos may be viewed at http://auditorymodels.org/ (Click Demos).
Cochlear tuning and phase-locking assessed with complementary techniques within the same species, and extrapolation to humans
Authors: Joris Philip X. , Verschooten Eric
Published: June 2017

The cochlea decomposes sound into bands of its constituent frequencies and encodes the temporal waveform of these bands. These two properties generate frequency-tuning and phase-locking in individual neurons of the auditory nerve. The relative roles of frequency tuning and phase-locking toward important aspects of perception, e.g., the coding of speech and pitch, are heavily debated. Characterization of the limits of these processes in humans may help to clarify these relative roles. We studied threshold and suprathreshold frequency tuning, as well as phase-locking to the fine-structure of sound, by recording from single-fibers in the auditory nerve of different species, including chinchilla, cat, and macaque monkey. We also developed stimulus and analysis paradigms to study frequency tuning and phase-locking via mass potentials recorded near the cochlear round window, and applied these techniques to these same species as well as to normal hearing human subjects. The comparison of bandwidths of single fibers with mass potentials within the same species allows us to infer bandwidths of single fibers from human mass potential data. Combined with behavioral and otoacoustic emission data, the evidence suggests that the human auditory nerve is unusual in its sharpness of frequency tuning but not in its range of phase-locking.
On the relationships between otoacoustic emissions, auditory evoked potentials, and psychoacoustical performance
Authors: McFadden Dennis , Pasanen Edward G. , Maloney Mindy M. , Leshikar Erin M. , Pho Michelle H. , Champlin Craig A.
Published: June 2017

Performance was measured on several common psychoacoustical tasks for about 70 subjects. The measures included simultaneous and temporal masking, masking by tones and by complex sounds, critical bandwidth, release from masking, and detection in the quiet. Also measured were spontaneous, click-evoked, and distortion-product otoacoustic emissions (OAEs) and auditory evoked potentials (AEPs, short and middle latency). Of interest were the correlations between psychoacoustical performance and the various physiological measures as well as any mean differences by sex and by menstrual cycle. Subjects were tested behaviorally in same-sex crews of 4–8 members, and behavioral testing required from 8 to 10 weeks for each crew. Correlation and effect size were the primary measures of interest. Resampling was used to determine implied significance for the various comparisons studied. Some correlations between physiological measures were moderately high, but the correlations between psychoacoustical tasks and the different physiological measures were generally low, although there were some unexpected differences by racial background. That is, the individual differences observed in psychoacoustical performance generally were not related to the individual differences in the various physiological measures. For these subjects, at least, psychoacoustical performance seemed unrelated to the mechanisms underlying OAEs and AEPs. [Work supported by NIDCD (DC000153).]
Imaging challenging media by full waveform inversion of ultrasonic signals
Authors: Moreau Ludovic , Brossier Romain , Métivier Ludovic
Published: June 2017

Austenitic welds are important parts of the cooling system in nuclear power plants, which undergo extreme temperature and pressure variations that may cause defects to appear in the welded zone. If not attended, these may lead to a leakage of radioactive liquids. It is therefore crucial to assess the structural integrity of austenitic welds by detecting and imaging such defects. Ultrasonic methods are one of the reference methods in this matter. Current imaging techniques rely on phased array technology to focus the ultrasonic energy based on beamforming approaches such as the total focusing method. Because the elastic properties and exact geometry of austenitic welds are unknown, these methods fail to produce a reliable image of the inspected area. We introduce the full waveform inversion (FWI) of ultrasonic signals as a promising alternative imaging method. Adapted from Geophysics, the FWI uses a numerical model to simulate the experiment, and iterates by updating the model until the error between experimental and synthetic data is minimized. The model inputs are elastic properties in the inspected area. Eventually, it converges towards a reliable representation of the actual weld, including its geometry, elastic properties, and defects.
Determination of the acetabular cup implant stability using an acoustic method based on the impact between the hammer and the ancillary
Authors: Rosi Giuseppe , Nguyen Vu-Hieu , Tijou Antoine , Bosc Romain , Haiat Guillaume
Published: June 2017

The hemispherical acetabular cup (AC) implant is used during total hip replacement surgery and is inserted in the acetabulum using impacts applied with an orthopedic hammer. However, the assessment of the AC implant primary stability remains difficult. The aim of this study was to investigate the feasibility of retrieving the AC implant stability based on impact signal analyses. AC implants with various sizes were inserted in 12 cadaveric hips following the same protocol as the one employed in the clinic. An instrumented hammer was then used to measure the variation of the force as a function of time produced during the impact between the hammer and the ancillary. Then, an indicator I was determined for each impact based on the impact momentum. A significant correlation (R² = 0.69) was found between I and the pull-out force. Moreover, a tridimensional axisymmetric finite element model was developed to simulate the insertion processes of the AC implant into bone tissue during impacts. The variation of the force applied between the hammer and the ancillary was analyzed and the numerical results were compared with the experimental results. The results show the potential of impact analysis to retrieve the bone-implant contact properties.
Optical absorption effect on laser-generated resonances in semi-transparent solid
Authors: Laurent Jérôme , Royer Daniel , Prada Claire
Published: June 2017

We studied the effect of optical absorption on the Lamb wave thermoelastic generation in isotropic plates. For metallic plates, high optical absorption results in a surface source and Lamb mode amplitudes depend on the total deposited energy and laser source shape. In the case of moderately absorbing plates, the laser beam can penetrate the sample to some optical depth, producing a bulk source. Consequently, the radiation characteristics of laser-ultrasound are significantly different. The displacement amplitudes can be controlled by the incidence angle of the laser beam and depend on the material absorption. We used a laser-based ultrasonic setup for the generation and detection of guided waves in semi-transparent plate-like structure. In a free elastic plate, resonances occur at Zero-Group Velocity (ZGV) points where the phase velocity remains finite. For studying the transition from a surface source to a bulk source we performed local measurements in neutral density filters having different absorbance. ZGV resonances amplitude increase with absorption until a maximum is reached depending on the order of the mode. Furthermore, these measurements allow to discriminate the so-called thickness resonances, associated to the precursors, from ZGV resonances. Finally, the experimental results are compared with semi-analytical simulations based on Spicer model.
High speed non-contact acoustic inspection method using long distance acoustic irradiation-induced vibration
Authors: Sugimoto Tsuneyoshi , Sugimoto Kazuko , Utagawa Noriyuki , Katakura Kageyoshi
Published: June 2017

The non-contact acoustic inspection method using air-borne sound can detect the cavity defect and crack of inside concrete near the surface. As a feature of this technique, focusing on the physical phenomenon of flexural vibration of defects, we succeed in improving energy efficiency to vibrate the defect effectively. It is possible to measure all day using a small dynamo. Moreover, using a low-output laser Doppler vibrometer (LDV), high signal to noise (S/N) ratio is achieved by our proposed broadband “Tone Burst Wave” and “Time & Frequency-gate (T-F gate).” Therefore, although a possible distance from a sound source and a LDV to target is dependent on output power of acoustic radiation, it was already confirmed that a measurement of long distance over 30 m away is possible under the condition that a target is excited efficiently. In order to shorten measurement time, we propose the “Multi Tone Burst wave” that fully utilized the principle of T-F gate. After many experiments using a concrete test objects and some experiments of real concrete structures (bridge, etc.), we confirmed the validity of high-speed measurement technique of the “Multi-Tone Burst wave.”
Vibro-acoustic beamforming technique for the detection of a monopole source inside a fluid-filled cylinder with turbulent flow: Numerical and experimental investigations
Authors: Kassab Souha , Laurent Maxit
Published: June 2017

This study takes part of the R&D framework on sodium-water steam generators, mainly used in the cooling of Fast Sodium Reactors. The aim is to develop a vibro-acoustic monitoring technique that can detect a leak of water into sodium from a defective tube inside the heat exchanger. In the presence of a significantly high background noise and a rather large bandwidth for the leak signature, threshold-detection methods might be insufficient. A beamforming technique is thus considered in order to enhance the leak’s signature against the nuclear facility’s background noise. The present study is carried out on a laboratory test case composed by a cylindrical shell filled with water which is coupled to a hydraulic circuit with two axisymmetric stiffeners. Two kind of excitations are considered: first is a monopole radiating inside the fluid-filled cylinder, the second is a well-established turbulent boundary layer at the neighborhood of the shell’s walls. Numerical simulations are performed to estimate the shell acceleration field used as input of the beamforming technique. Additionally, an experiment is carried out on a mock-up to study the correlations between the numerical and experimental results associated with each excitation. The theoretical and experimental performances of the beamforming are also compared.
Design of tunable acoustic metamaterials using 3D computer graphics
Authors: Cops Mark J. , McDaniel James G. , Magliula Elizabeth A.
Published: June 2017

The goal of this work is to investigate how the combination of 3D computer graphics and finite element software can be used to rapidly design materials with tunable properties for noise and vibration mitigation applications. Algorithms and software that create three-dimensional objects, known collectively as 3D computer graphics, are widely used artistically for rendering, animation, and game creation. These approaches allow for the design of complex topological structures such as cellular solids. This presentation describes the use of 3D computer graphics to design cellular structures, which can be imported into finite element software in order to determine effective vibrational properties. This approach is advantageous for several reasons. It allows for quick variation of parameters of cellular solids such as porosity and void fraction. It also is time efficient compared to alternative methods such as performing computed tomography scans on physical samples and analyzing the imaged files. Furthermore, resulting designs can be easily fabricated by direct 3D printing. This presentation will include analysis and discussion of designs generated by the proposed approach.