Speech audibility for listeners with high-frequency hearing loss.

This study investigated whether there are limitations on the benefit of providing audible speech information to listeners with high-frequency hearing loss. In a group of 10 listeners with various degrees of high-frequency hearing loss, speech recognition was tested across a wide range of presentation levels. For each of these listeners with hearing loss, recognition performance reached an asymptote of < 100%. When the spectrum of the speech for this asymptotic performance level was compared with the listener's pure-tone thresholds, it was seen that providing audible speech to high-frequency regions (> or = 3000 Hz), where hearing loss exceeds 55 dB HL, tended to produce little or no improvement in recognition scores. In contrast, providing audible speech to lower frequency regions for a listener with a flat, severe-to-profound hearing loss did show improvement with increasing speech audibility, despite this listener's thresholds being greater than 55 dB HL. The present study adds further support to the idea that attempting to provide amplification to regions with severe high-frequency hearing loss (> or = 3000 Hz) may not necessarily benefit many individuals with hearing loss.