Speaking Clearly for the Hard of Hearing I

TLDR

The study examines how speech intelligibility differs for hearing‑impaired listeners when spoken clearly versus conversationally. The authors measured intelligibility differences by testing five sensorineural‑hearing‑loss listeners on nonsense sentences spoken clearly and conversationally by three male talkers across varying levels and frequency‑gain settings. Clear speech was on average 17 percentage points more intelligible than conversational speech, a difference that was largely independent of listener, level, or frequency‑gain, and improvements were seen across all phoneme classes.

Abstract

This paper is concerned with variations in the intelligibility of speech produced for hearing-impaired listeners under two conditions. Estimates were made of the magnitude of the intelligibility differences between attempts to speak clearly and attempts to speak conversationally. Five listeners with sensorineural hearing losses were tested on groups of nonsense sentences spoken clearly and conversationally by three male talkers as a function of level and frequency-gain characteristic. The average intelligibility difference between clear and conversational speech averaged across talker was found to be 17 percentage points. To a first approximation, this difference was independent of the listener, level, and frequency-gain characteristic. Analysis of segmental-level errors was only possible for two listeners and indicated that improvements in intelligibility occurred across all phoneme classes.