Acoustic change complex in background noise: phoneme level and timing effects.
| Autor: | Billings CJ; National Center for Rehabilitative Auditory Research Veterans Affairs Portland Health Care System, Portland, Oregon Curtis.Billings2@va.gov.; Department of Otolaryngology, Oregon Health & Science University, Portland, Oregon., Grush LD; National Center for Rehabilitative Auditory Research Veterans Affairs Portland Health Care System, Portland, Oregon., Maamor N; National Center for Rehabilitative Auditory Research Veterans Affairs Portland Health Care System, Portland, Oregon.; Audiology Program School of Rehabilitation Sciences Faculty of Health Sciences The National University of Malaysia, Kuala Lumpur, Malaysia. |
|---|---|
| Jazyk: | angličtina |
| Zdroj: | Physiological reports [Physiol Rep] 2017 Nov; Vol. 5 (20). |
| DOI: | 10.14814/phy2.13464 |
| Abstrakt: | The effects of background noise on speech-evoked cortical auditory evoked potentials (CAEPs) can provide insight into the physiology of the auditory system. The purpose of this study was to determine background noise effects on neural coding of different phonemes within a syllable. CAEPs were recorded from 15 young normal-hearing adults in response to speech signals /s/, /ɑ/, and /sɑ/. Signals were presented at varying signal-to-noise ratios (SNRs). The effects of SNR and context (in isolation or within syllable) were analyzed for both phonemes. For all three stimuli, latencies generally decreased and amplitudes generally increased as SNR improved, and context effects were not present; however, the amplitude of the /ɑ/ response was the exception, showing no SNR effect and a significant context effect. Differential coding of /s/ and /ɑ/ likely result from level and timing differences. Neural refractoriness may result in the lack of a robust SNR effect on amplitude in the syllable context. The stable amplitude across SNRs in response to the vowel in /sɑ/ suggests the combined effects of (1) acoustic characteristics of the syllable and noise at poor SNRs and (2) refractory effects resulting from phoneme timing at good SNRs. Results provide insights into the coding of multiple-onset speech syllables in varying levels of background noise and, together with behavioral measures, may help to improve our understanding of speech-perception-in-noise difficulties. (© 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.) |
| Databáze: | MEDLINE |
| Externí odkaz: |
|