Improved speech recognition in noise in simulated binaurally combined acoustic and electric stimulation

摘要

Combined acoustic and electric stimulation does more to help speech recognition in noise than electric stimulation alone. In this work the contribution of fundamental frequency (FO) and low-frequency phonetic cues to speech recognition in combined hearing is investigated. Normal-hearing listeners heard vocoded speech in one ear and low-pass (LP) filtered speech in the other. Three listening conditions (vocode-alone, LP-alone, combined) were investigated. Target speech (average F0=120 Hz) was mixed with a time-reversed masker (average F0=172 Hz) at three signal-to-noise ratios (SNRs). LP speech aided performance at all SNRs. Low-frequency phonetic cues were then removed by replacing the LP speech with a LP equal-amplitude harmonic complex, frequency and amplitude modulated by the FO and temporal envelope of voiced segments of the target. The combined hearing advantage disappeared at 10 and 15 dB SNR, but persisted at 5 dB SNR.