Spatial hearing abilities of bilateral hearing-aid users

Most research into the spatial hearing abilities of bilateral hearing-aid users has dealt with unrealistically simple test situations. We therefore investigated their performance on spatially complex, multi-talker listening tasks. Our results revealed substantial inter-listener differences, which appeared to be related to auditory and cognitive factors.

Cocktail-party listening and cognitive skills

Hearing-impaired listeners are known to experience certain problems in situations with multiple competing speech signals, e.g. cocktail parties. In order to investigate hearing-aid users’ performance on competing-speech tasks, we developed a Danish multi-talker speech corpus based on the Dantale-II material.

Together with researchers from the University of Sydney, we then carried out a study where we fitted twenty hearing-impaired listeners with bilateral completely-in-the-canal hearing aids that had been adjusted to ensure high-frequency speech audibility as well as minimal distortion of spatial acoustic cues. Following an acclimatisation period of about four weeks, we measured the listeners’ performance on a number of competing-speech tasks that differed in spatial complexity. Furthermore, we measured their working memory and attention skills.

Results

Our results showed that performance differed substantially across listeners. This variability, which increased with spatial complexity, could partly be explained by differences in hearing sensitivity and cognitive function. We therefore concluded that poorer sensitivity to spatial acoustic cues as well as reduced cognitive function may impair speech understanding in situations like cocktail parties.

Further reading

Behrens T, Neher T, Johannesson RB (2008). Evaluation of speech corpus for assessment of spatial release from masking. In: Dau T, Buchholz JM, Harte J. Christiansen TU (Eds.) Auditory Signal Processing in Hearing-Impaired Listeners. Proceedings of the First International Symposium on Audiological and Auditory Research, ISAAR, p. 449-457.

Neher T, Behrens T, Carlile S, Jin C, Kragelund L, Petersen AS, van Schaik A (2009). Benefit from spatial separation of multiple talkers in bilateral hearing-aid users: Effects of hearing loss, age, and cognition. International Journal of Audiology, 48(11), p. 758-774.