Temporally smeared speech: Its intelligibility and its relationship to temporal resolution

Abstract

In the past, the effects of deteriorated temporal resolution of the auditory system on speech intelligibility have been studied by measuring the correlation between temporal resolution and speech perception using hearing impaired listeners. These studies have not given consistent results. In the ongoing study, an alternative approach was explored. Essentially, envelopes of speech were temporally smeared in 23 parallel frequency channels. The smeared speech was presented to normal-hearing listeners, and the effects of different smearing magnitudes on speech intelligibility were measured by obtaining direct speech recognition scores. The auditory representations of the smeared stimuli have reduced temporal resolution but nearly normal frequency resolution. The principle of the smearing processing will be discussed. Data on temporal resolution and frequency selectivity obtained using smeared stimuli and normal subjects will be presented. Speech intelligibility of smeared nonsense syllables was also tested.