Spatially separated speech sources improve intelligibility through binaural release from masking.

Evidence

When listening to speech in a noisy background, higher speech intelligibility is measured for spatially separated speech and interfering sources, as compared to collocated sources. The benefit of this spatial separation, known as spatial release from masking, has been attributed to binaural processing enabling a better signal detection, as can be measured by binaural masking level differences (BMLDs). These BMLDs describe the difference in thresholds for tone-in-noise detection when both the target tone and masking noise are presented interaurally in phase, in contrast to a reversed phase of the tone in one ear. In the latter case thresholds are significantly lower. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1620

In the context of speech communication, spatial release from masking (SRM) refers to an improvement in intelligibility when competing sounds are spatially separated from the talker of interest. This improvement can arise as a result of acoustic benefits (such as the “head-shadow” advantage) or by effective increases in signal-to-noise ratio resulting from neural processing of binaural cues (so called “masking level differences”). In other cases it appears that the perceived separation of sources drives the advantage by enabling attention to be directed selectively. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1723

When listening to speech in a noisy background, higher speech intelligibility is measured for spatially separated speech and interfering sources, as compared to collocated sources. The benefit of this spatial separation, known as spatial release from masking, has been attributed to binaural processing enabling a better signal detection, as can be measured by binaural masking level differences (BMLDs). These BMLDs describe the difference in thresholds for tone-in-noise detection when both the target tone and masking noise are presented interaurally in phase, in contrast to a reversed phase of the tone in one ear. In the latter case thresholds are significantly lower. Similar interaural relations of the stimuli can be achieved by presenting the noise from a spatial position directly in front of the listener and the signal from a different spatial location. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1621

Categorization

• XREF: Connects to the reader’s general knowledge of psychoacoustics and the binaural masking level difference literature. — connects to: Binaural intelligibility level difference measures speech unmasking benefit — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1513
• DEFINE: Defines spatial release from masking and distinguishes its three candidate mechanisms, the conceptual core of the chapter.
• corroborated: 6 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 1620; Dijk, Pim van, Physiology, Psychoacoustics and…, 1723; Dijk, Pim van, Physiology, Psychoacoustics and…, 1621