Predict the intelligibility of individual consonants in noise for hearing-impaired listeners.

Abstract

The performance of hearing-impaired (HI) listeners to understand speech often deteriorates drastically in cocktail-party environments. To understand why a particular HI listener can hear certain sounds and not the others, it is critical that we take the prior knowledge about speech cues into consideration and investigate the effect of different types of cochlear hearing loss on speech perception. In the last 2 years we have tested over 50 hearing-impaired ears on consonant identification in noise. To evaluate the impact of shift of hearing threshold on the intelligibility of individual consonants in masking noise, a consonant intelligibility index (CII) is developed to predict the perceptual scores of individual consonants. Results of preliminary study indicate that CII makes an accurate prediction for flat mild-to-moderate hearing loss, but fails for the cases of cochlear dead region and extremely unbalanced (e.g., severe high-frequency) loss, suggesting that audibility alone does not fully account for the hard of speech perception in noise for many HI listeners.