The influence of masker type on early reflection processing and speech intelligibility (L)

Arweiler and Buchholz [J. Acoust. Soc. Am. 130, 996-1005 (2011)] showed that, while the energy of early reflections (ERs) in a room improves speech intelligibility, the benefit is smaller than that provided by the energy of the direct sound (DS). In terms of integration of ERs and DS, binaural listening did not provide a benefit from ERs apart from a binaural energy summation, such that monaural auditory processing could account for the data. However, a diffuse speech shaped noise (SSN) was used in the speech intelligibility experiments, which does not provide distinct binaural cues to the auditory system. In the present study, the monaural and binaural benefit from ERs for speech intelligibility was investigated using three directional maskers presented from 90° azimuth: a SSN, a multi-talker babble, and a reversed two-talker masker. For normal-hearing as well as hearing-impaired listeners, the directional and/or fluctuating (speech) maskers produced a similar benefit from ERs as obtained with the diffuse SSN, suggesting a monaural integration of the ERs and the DS for both types of maskers.