Speech Perception with Spectrally Non-overlapping Maskers as Measure of Spectral Resolution in Cochlear Implant Users
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Poor spectral resolution contributes to the difficulties experienced by cochlear implant (CI) users when listening to speech in noise. However, correlations between measures of spectral resolution and speech perception in noise have not always been found to be robust. It may be that the relationship between spectral resolution and speech perception in noise becomes clearer in conditions where the speech and noise are not spectrally matched, so that improved spectral resolution can assist in separating the speech from the masker. To test this prediction, speech intelligibility was measured with noise or tone maskers that were presented either in the same spectral channels as the speech or in interleaved spectral channels. Spectral resolution was estimated via a spectral ripple discrimination task. Results from vocoder simulations in normal-hearing listeners showed increasing differences in speech intelligibility between spectrally overlapped and interleaved maskers as well as improved spectral ripple discrimination with increasing spectral resolution. However, no clear differences were observed in CI users between performance with spectrally interleaved and overlapped maskers, or between tone and noise maskers. The results suggest that spectral resolution in current CIs is too poor to take advantage of the spectral separation produced by spectrally interleaved speech and maskers. Overall, the spectrally interleaved and tonal maskers produce a much larger difference in performance between normal-hearing listeners and CI users than do traditional speech-in-noise measures, and thus provide a more sensitive test of speech perception abilities for current and future implantable devices.
Keywordsmasking release current spread spectral separation speech in noise
This research was supported by NIDCD Grant R01 DC012262. The authors wish to extend special thanks to the participants in this study.
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Conflict of Interest
The authors declare that they have no conflict of interest.
- Gifford RH, Noble JH, Camarata SM et al (2018) The relationship between spectral modulation detection and speech recognition: adult versus pediatric cochlear implant recipients. Trends Hear 22:1–14Google Scholar
- IEEE (1969) IEEE recommended practices for speech quality measurements. IEEE Trans Audio Electroacoust 17:227–246Google Scholar
- Landsberger DM, Padilla M, Martinez AS, Eisenberg LS (2017) Spectral-temporal modulated ripple discrimination by children with Cochlear implants. Ear Hear 39:60–68Google Scholar
- Oxenham AJ, Kreft HA (2014) Speech perception in tones and noise via cochlear implants reveals influence of spectral resolution on temporal processing. Trends Hear 18:1–14Google Scholar
- Wilson JP, Evans EF (1971) Grating acuity of the ear: psychophysical and neurophysiological measures of frequency resolving power. Proc 7th Int Congr AcoustGoogle Scholar