TY - JOUR

T1 - Do cochlear mechanisms explain the noise-disruption of the auditory brainstem response to speech?

AU - Nuttall, Helen

AU - Heinrich, Antje

AU - Moore, David

AU - de Boer, Jessica

PY - 2013/5/1

Y1 - 2013/5/1

N2 - In background noise, the timing precision of the auditory brainstem response to speech (speech-ABR) is disrupted and the response latency increases. The severity of the disruption has been correlated with listeners' ability to understand speech-in-noise. To date, although a central mechanism is assumed, the locus of the speech-ABR timing disruption is not clear. The present study aimed to investigate the contribution of different cochlear mechanisms to noise-induced latency increases. A first experiment examined the 'cochlear place' mechanism, by which the latency of the response increases as cochlear origin moves towards lower frequency regions. The results showed that the speech-ABR reflects an average over responses from a broad range of cochlear regions, which respond with substantial relative delays. This implies that cochlear place can potentially have large effects on masked speech-ABR latency. Another mechanism that is known to be involved in noise-induced ABR latency increases is neural adaptation. This is presumed to occur at the inner hair cell-nerve junction and is thought to reflect cochlear masking. Thus, if this mechanism contributes to speech-ABR latency increases in noise, we would expect this contribution to depend on cochlear frequency selectivity and amplification gain. This hypothesis is tested in the second experiment.

AB - In background noise, the timing precision of the auditory brainstem response to speech (speech-ABR) is disrupted and the response latency increases. The severity of the disruption has been correlated with listeners' ability to understand speech-in-noise. To date, although a central mechanism is assumed, the locus of the speech-ABR timing disruption is not clear. The present study aimed to investigate the contribution of different cochlear mechanisms to noise-induced latency increases. A first experiment examined the 'cochlear place' mechanism, by which the latency of the response increases as cochlear origin moves towards lower frequency regions. The results showed that the speech-ABR reflects an average over responses from a broad range of cochlear regions, which respond with substantial relative delays. This implies that cochlear place can potentially have large effects on masked speech-ABR latency. Another mechanism that is known to be involved in noise-induced ABR latency increases is neural adaptation. This is presumed to occur at the inner hair cell-nerve junction and is thought to reflect cochlear masking. Thus, if this mechanism contributes to speech-ABR latency increases in noise, we would expect this contribution to depend on cochlear frequency selectivity and amplification gain. This hypothesis is tested in the second experiment.

U2 - 10.1121/1.4792844

DO - 10.1121/1.4792844

M3 - Journal article

VL - 19

JO - Proceedings of Meetings on Acoustics

JF - Proceedings of Meetings on Acoustics

SN - 1939-800X

IS - 1

M1 - 050119

ER -