Document Type

Article

Publication Date

9-1-2016

Keywords

cue weighting, cochlear implant, bimodal hearing, spectral degradation

Digital Object Identifier (DOI)

https://doi.org/10.1177/2331216516652145

Abstract

Multiple redundant acoustic cues can contribute to the perception of a single phonemic contrast. This study investigated the effect of spectral degradation on the discriminability and perceptual saliency of acoustic cues for identification of word-final fricative voicing in “loss” versus “laws”, and possible changes that occurred when low-frequency acoustic cues were restored. Three acoustic cues that contribute to the word-final /s/-/z/ contrast (first formant frequency [F1] offset, vowel–consonant duration ratio, and consonant voicing duration) were systematically varied in synthesized words. A discrimination task measured listeners’ ability to discriminate differences among stimuli within a single cue dimension. A categorization task examined the extent to which listeners make use of a given cue to label a syllable as “loss” versus “laws” when multiple cues are available. Normal-hearing listeners were presented with stimuli that were either unprocessed, processed with an eight-channel noise-band vocoder to approximate spectral degradation in cochlear implants, or low-pass filtered. Listeners were tested in four listening conditions: unprocessed, vocoder, low-pass, and a combined vocoder + low-pass condition that simulated bimodal hearing. Results showed a negative impact of spectral degradation on F1 cue discrimination and a trading relation between spectral and temporal cues in which listeners relied more heavily on the temporal cues for “loss-laws” identification when spectral cues were degraded. Furthermore, the addition of low-frequency fine-structure cues in simulated bimodal hearing increased the perceptual saliency of the F1 cue for “loss-laws” identification compared with vocoded speech. Findings suggest an interplay between the quality of sensory input and cue importance.

Rights Information

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 3.0 License

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Yes

Citation / Publisher Attribution

Trends in Hearing, v. 20, p. 1-15

Kong,Y., Winn, M. B., Poellmann, K. & Donaldson, G. S., Discriminability and Perceptual Saliency of Temporal and Spectral Cues for Final Fricative Consonant Voicing in Simulated Cochlear-Implant and Bimodal Hearing. Trends in Hearing, (20) 1-15. © The Authors 2015. Reprinted by permission of SAGE Publications.

The final authenticated version is available online at: https://doi.org/10.1177/2331216516652145.

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