Discriminability and Perceptual Saliency of Temporal and Spectral Cues for Final Fricative Consonant Voicing in Simulated Cochlear-Implant and Bimodal Hearing
| Autor: | Ying-Yee Kong, Matthew B. Winn, Katja Poellmann, Gail S. Donaldson |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Trends in Hearing, Vol 20 (2016) |
| Druh dokumentu: | article |
| ISSN: | 2331-2165 23312165 |
| DOI: | 10.1177/2331216516652145 |
| Popis: | 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. |
| Databáze: | Directory of Open Access Journals |
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