Year: 2019
Type: dissertation
Abstract: People with hearing loss often struggle to understand speech in the presence of \nbackground noise. The features of the interfering noise source, and where the sounds are \nlocated in the environment with reference to the listener’s position, influence the degree \nof difficulties faced by the listener. \nThose with hearing-impairment demonstrate a substantial loss in the intelligibility \nof speech in the presence of interfering noise sources, when compared to their normal- \nhearing counterparts. The ability to use dips in the envelope of the interfering source, \nfundamental frequency and spatial processing all become less useful for the person with \nhearing loss. This deficit cannot simply be explained by a reduction in audibility. \nLip-reading provides an important cue for speech intelligibility and the advice \ngiven to those with hearing loss is to face the speaker of interest directly. The Jelfs et al. \n(2011) model predicts substantial benefit of orientating the head away from the target \nspeech in normal-hearing listeners. This has since been confirmed by Grange and \nCulling (2016) in normal-hearing listeners. Hearing-impaired listeners were found to \ngain a similar level of benefit by orientating the head away from the target. This has \nramifications for audiology services and the advice provided by clinicians. When \ninterference comes predominantly from one side, the listener is advised to turn the head \n30° away from the target talker and toward the interferers. \nA major problem with studying the hearing-impaired population is the variability \nin performance on measures that underpin speech intelligibility in noise. This causes an \nissue when making comparisons with the normal-hearing population. An approach to \nexamining the relevance of individual performance measures to overall speech \nintelligibility is to make a median split based on each measure, and then compare the \nspeech-in-noise performance of the resulting groups. Measures of binaural temporal fine \nstructure processing, processing of level and time differences independently and \ncontralateral masking were used to explore the factors that lead to poor use of spatial \ncues by hearing-impaired listeners. No explanation for the poor use of spatial cues could \nbe found in these measures.
Author: Barry Bardsley
Language: English
Subfield: Speech and Hearing
Field: Health Professions
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W3005080579