Directional source allocation, not binaural unmasking, explains spatial release

Evidence

The stable spatial release from masking over the range of SNR criteria tested is one of the most important outcomes of this study. It suggests that recovery of sub-threshold speech information by binaural cues does not play a role in the spatial release from masking in a multispeaker situation. Instead, masking release appeared to be sustained even when only high-SNR components of target speech were left in the signal. These supra-threshold components should be detectable monaurally in both the collocated and spatially separated conditions and thus their detection should not rely on a binaural unmasking mechanism as is the case for BMLDs. An explanation for this spatial release from masking can be provided by directional cues of the stimuli that support a better allocation of speech components to the source of interest. The fact that speech sources originate from different spatial positions can eliminate some confusion that arises from the simultaneous presence of multiple speech sources (Durlach et al. 2003 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 1619

Categorization

• XREF: Ties SRM to informational masking / source confusion rather than energetic binaural unmasking — connects to the reader’s broader interest in how the auditory system allocates streams.
• SEED: An angle: the finding that SRM survives removal of all low-SNR components argues spatial hearing works via source segregation and attention, not sub-threshold recovery — a candidate for a piece on what actually underlies the cocktail-party effect.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 1619