scholarly journals Mechanisms of Spectrotemporal Modulation Detection for Normal- and Hearing-Impaired Listeners

2021 ◽  
Vol 25 ◽  
pp. 233121652097802
Author(s):  
Emmanuel Ponsot ◽  
Léo Varnet ◽  
Nicolas Wallaert ◽  
Elza Daoud ◽  
Shihab A. Shamma ◽  
...  

Spectrotemporal modulations (STM) are essential features of speech signals that make them intelligible. While their encoding has been widely investigated in neurophysiology, we still lack a full understanding of how STMs are processed at the behavioral level and how cochlear hearing loss impacts this processing. Here, we introduce a novel methodological framework based on psychophysical reverse correlation deployed in the modulation space to characterize the mechanisms underlying STM detection in noise. We derive perceptual filters for young normal-hearing and older hearing-impaired individuals performing a detection task of an elementary target STM (a given product of temporal and spectral modulations) embedded in other masking STMs. Analyzed with computational tools, our data show that both groups rely on a comparable linear (band-pass)–nonlinear processing cascade, which can be well accounted for by a temporal modulation filter bank model combined with cross-correlation against the target representation. Our results also suggest that the modulation mistuning observed for the hearing-impaired group results primarily from broader cochlear filters. Yet, we find idiosyncratic behaviors that cannot be captured by cochlear tuning alone, highlighting the need to consider variability originating from additional mechanisms. Overall, this integrated experimental-computational approach offers a principled way to assess suprathreshold processing distortions in each individual and could thus be used to further investigate interindividual differences in speech intelligibility.

2020 ◽  
Author(s):  
Emmanuel Ponsot ◽  
Léo Varnet ◽  
Nicolas Wallaert ◽  
Elza Daoud ◽  
Shihab A. Shamma ◽  
...  

AbstractSpectrotemporal modulations (STMs) offer a unified framework to probe suprathreshold auditory processing. Here, we introduce a novel methodological framework based on psychophysical reverse-correlation deployed in the modulation space to characterize how STMs are detected by the auditory system and how cochlear hearing loss impacts this processing. Our results show that young normal-hearing (NH) and older hearing-impaired (HI) individuals rely on a comparable non-linear processing architecture involving non-directional band-pass modulation filtering. We demonstrate that a temporal-modulation filter-bank model can capture the strategy of the NH group and that a broader tuning of cochlear filters is sufficient to explain the overall shift toward temporal modulations of the HI group. Yet, idiosyncratic behaviors exposed within each group highlight the contribution and the need to consider additional mechanisms. This integrated experimental-computational approach offers a principled way to assess supra-threshold auditory processing distortions of each individual.


2021 ◽  
Vol 25 ◽  
pp. 233121652110144
Author(s):  
Ilja Reinten ◽  
Inge De Ronde-Brons ◽  
Rolph Houben ◽  
Wouter Dreschler

Single microphone noise reduction (NR) in hearing aids can provide a subjective benefit even when there is no objective improvement in speech intelligibility. A possible explanation lies in a reduction of listening effort. Previously, we showed that response times (a proxy for listening effort) to an auditory-only dual-task were reduced by NR in normal-hearing (NH) listeners. In this study, we investigate if the results from NH listeners extend to the hearing-impaired (HI), the target group for hearing aids. In addition, we assess the relevance of the outcome measure for studying and understanding listening effort. Twelve HI subjects were asked to sum two digits of a digit triplet in noise. We measured response times to this task, as well as subjective listening effort and speech intelligibility. Stimuli were presented at three signal-to-noise ratios (SNR; –5, 0, +5 dB) and in quiet. Stimuli were processed with ideal or nonideal NR, or unprocessed. The effect of NR on response times in HI listeners was significant only in conditions where speech intelligibility was also affected (–5 dB SNR). This is in contrast to the previous results with NH listeners. There was a significant effect of SNR on response times for HI listeners. The response time measure was reasonably correlated ( R142 = 0.54) to subjective listening effort and showed a sufficient test–retest reliability. This study thus presents an objective, valid, and reliable measure for evaluating an aspect of listening effort of HI listeners.


1976 ◽  
Vol 19 (2) ◽  
pp. 279-289 ◽  
Author(s):  
Randall B. Monsen

Although it is well known that the speech produced by the deaf is generally of low intelligibility, the sources of this low speech intelligibility have generally been ascribed either to aberrant articulation of phonemes or inappropriate prosody. This study was designed to determine to what extent a nonsegmental aspect of speech, formant transitions, may differ in the speech of the deaf and of the normal hearing. The initial second formant transitions of the vowels /i/ and /u/ after labial and alveolar consonants (/b, d, f/) were compared in the speech of six normal-hearing and six hearing-impaired adolescents. In the speech of the hearing-impaired subjects, the second formant transitions may be reduced both in time and in frequency. At its onset, the second formant may be nearer to its eventual target frequency than in the speech of the normal subjects. Since formant transitions are important acoustic cues for the adjacent consonants, reduced F 2 transitions may be an important factor in the low intelligibility of the speech of the deaf.


2018 ◽  
Vol 22 ◽  
pp. 233121651880270 ◽  
Author(s):  
Jacques A. Grange ◽  
John F. Culling ◽  
Barry Bardsley ◽  
Laura I. Mackinney ◽  
Sarah E. Hughes ◽  
...  

2015 ◽  
Author(s):  
Virginia Best ◽  
Christine R. Mason ◽  
Jayaganesh Swaminathan ◽  
Elin Roverud ◽  
Gerald Kidd

Author(s):  
Paris Binos

Vocants are precursors to speech and are facially neutral. The presence of these speechlike vocalizations was evident during the precursors to mature phonology called “protophones”. The prosodic feature of duration of the nuclei plays a crucial role in the shift of prelexical to mature speech, since speech intelligibility is closely related to the control of duration. The aim of this work is to determine whether cochlear implants (CIs) positively trigger language acquisition and the development of verbal skills. Recent literature findings are compared and discussed with the performance of two Greek congenitally hearing-impaired infants who were matched with three normal-hearing (NH) infants. This work highlighted an important weakness of the prosodic abilities of young infants with CIs.


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