Simulating the effect binaural (electric and acoustic) hearing on Mandarin speech recognition under background noise for patients with cochlear implant (CI)

Abstract

This study evaluated the effects of binaurally combined electric and acoustic hearing on Mandarin speech recognition under simulated background noise for normal‐hearing (NH) listeners and CI recipients of the Nucleus‐24 device with contralateral hearing aid (HA). Chinese word and tone recognition were measured in seven NH subjects using simulated four‐channel continuous interleaved sampler (CIS) type speech processing strategy under three different conditions, namely, (1) only simulated (CI) signals with modulated Gaussian white noise for monaural stimulation, (2) simulated (CI) signals with modulated Gaussian white noise and simulated HA signals (low‐pass speech signals with cutoff frequency of 500 Hz) for monaural stimulation, and (3) simulated (CI) signals with modulated Gaussian white noise to one ear and simulated hearing aid (HA) signals to the other ear for dichotic stimulation. For comparison purposes, Chinese word and tone recognition were also measured in three CI users using advanced combination encoding (ACE) strategy. Preliminary results showed that the Chinese word and tone recognition rates of the NH listeners and CI recipients are statistically significantly improved (word and tone recognition rates were improved from 3.85% to 60.86% and 40.14% to 97.43% for NH listeners and 20% to 37.5% and 50% to 90% for CI recipients).