Speech Intelligibility Evaluation of Sound Coding Strategies  in Noisy Environments for Thai Cochlear Implant Users

Siriporn Dachasilaruk; Apichai Rungruang

doi:10.14456/nujst.2018.29

Authors

Siriporn Dachasilaruk Department of Electrical and Computer Engineering, Faculty of Engineering, Naresuan University
Apichai Rungruang Department of English Language, Faculty of Humanities, Naresuan University

DOI:

https://doi.org/10.14456/nujst.2018.29

Keywords:

cochlear implant, sound coding, speech intelligibility, filter bank, hearing loss

Abstract

The paper presents the effect of sound coding strategies on speech intelligibility of Thai-speaking cochlear implant (CI) users. Two sound coding strategies, namely continuous interleaved sampling (CIS) and advanced combination encoder (ACE) strategies were evaluated for word recognition. The tested words consisting of monosyllabic and bisyllabic words were corrupted by speech shaped noise and babble noise at SNR levels of 0, 5, 10 and 15 dB. The vocoded speech of clean and noisy words were tested by twelve normal-hearing listeners. The experimental results showed that speech intelligibility of the ACE strategy had higher mean scores than that of the CIS strategy in all tested conditions. The ACE strategy provided a significant speech intelligibility at SNR levels of 5 and 10 dB for monosyllabic words with speech shaped noise and at SNR levels of 0 dB for bisyllabic words with speech shaped noise. In addition, the noisy bisyllabic words provided higher intelligibility performance than the noisy monosyllabic words in all tested conditions.

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