|Best, V., Thompson,
Mason, C. R. and Kidd, G., Jr. (2011) Interactions
hearing loss and the spectral overlap of competing sounds in masked
J. Acoust. Soc. Am. 129(4
Pt. 2), pp. 2590.
This experiment explored the ideas
that energetic masking (EM) limits thebenefit achievable from spatial
separation in a competing speech task andthat differences in EM between
normalhearing (NH) and hearingimpaired (HI)listeners can explain
differences in spatial release from masking (SRM). Targetsentences and
similar masker sentences (or in another condition, masker noises)were
filtered into four narrow spectral bands and presented
simultaneously.The spectral overlap of the target and masker bands was
varied from minimal(interleaved bands) to maximal (identical bands).
Both NH and HI listenersshowed spectral tuning, such that masking by
noise or speech was reduced asspectral overlap was reduced. In fact,
this signal processing often improvedintelligibility relative to that
seen with unfiltered speech. Moreover, thresholdsin the noise and
speech maskers were closely related, suggesting that EM wasthe main
factor limiting performance across tasks. More masking was foundin HI
as compared to NH listeners for all spectral overlaps and both
maskers,and the HI group generally had less SRM. However, variations in
spectral overlapdid not lead to dramatic changes in SRM or in the
difference in SRM observed between groups.