Frequency-Limiting Effects on Speech and Environmental Sound Identification for Cochlear Implant and Normal Hearing Listeners

Son-A Chang, Jong Ho Won, HyangHee Kim, Seung-Ha Oh, Richard S. Tyler, Chang Hyun Cho
2018 Journal of Audiology and Otology  
and Objectives: It is important to understand the frequency region of cues used, and not used, by cochlear implant (CI) recipients. Speech and environmental sound recognition by individuals with CI and normal-hearing (NH) was measured. Gradients were also computed to evaluate the pattern of change in identification performance with respect to the low-pass filtering or high-pass filtering cutoff frequencies. Subjects and Methods: Frequency-limiting effects were implemented in the acoustic
more » ... ms by passing the signals through low-pass filters (LPFs) or high-pass filters (HPFs) with seven different cutoff frequencies. Identification of Korean vowels and consonants produced by a male and female speaker and environmental sounds was measured. Crossover frequencies were determined for each identification test, where the LPF and HPF conditions show the identical identification scores. Results: CI and NH subjects showed changes in identification performance in a similar manner as a function of cutoff frequency for the LPF and HPF conditions, suggesting that the degraded spectral information in the acoustic signals may similarly constraint the identification performance for both subject groups. However, CI subjects were generally less efficient than NH subjects in using the limited spectral information for speech and environmental sound identification due to the inefficient coding of acoustic cues through the CI sound processors. Conclusions: This finding will provide vital information in Korean for understanding how different the frequency information is in receiving speech and environmental sounds by CI processor from normal hearing. J Audiol Otol 2018;22(1):28-38 KEY WORDS:0 Frequency information · Cross-over frequency · Korean speech sound · Environmental sound · Cochlear implant. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
doi:10.7874/jao.2017.00178 pmid:29325391 pmcid:PMC5784366 fatcat:axy6qql4kzg6da6ieqepwp5rfu