The role of consonant duration and amplitude processing on speech intelligibility in noise

Hearing loss can have drastic effects on communication abilities leading researchers to strive to find solutions for the associated problems. Clear speech has been studied in the past as a possible avenue for improving speech understanding in those with hearing loss. In the present study, two characteristics of clear speech, increased consonant duration and consonant amplification, were applied to Hearing-in-Noise Test sentences. Stimuli were presented in sound field to hearing-impaired and normal-hearing individuals in the presence of speech-shaped noise, and percentage correct was measured. For HINT sentence presentations, both groups showed improvements for both amplitude and duration processing. Specifically, significant improvements were observed for the 10-dB condition for amplitude processing and the 15-ms condition for duration processing. Results show that increasing consonant duration and amplitude is a viable approach to improving speech understanding; nevertheless, this data suggest that there is a cutoff point where lengthening the duration of a consonant can result in a degraded speech signal.