Contribution of binaural masking release to improved speech intelligibility for different masker types

Abstract

In situations with competing talkers or in the presence of masking noise, speech intelligibility can be improved by spatially separating the target speaker from the interferers. This advantage is generally referred to as spatial release from masking, and different mechanisms have been suggested to explain it. One proposed mechanism to benefit from spatial cues is the binaural masking release, which is purely stimulus-driven. According to this mechanism, the spatial benefit results from differences in the binaural cues of target and masker, which need to appear simultaneously in time and frequency to improve the signal detection. In an alternative proposed mechanism, the differences in the interaural cues improve the segregation of auditory streams, a process, which involves top-down processing rather than being purely stimulus-driven. Other than the cues that produce binaural masking release, the interaural cue differences between target and interferer required to improve stream segregation do not have to appear simultaneously in time and frequency. This study is concerned with the contribution of binaural masking release to spatial release from masking for three masker types that differ with respect to the amount of energetic masking they exert. Speech intelligibility was measured, employing a stimulus manipulation that inhibits binaural masking release and analysed with a metric to account for the number of better-ear glimpses. Results indicate that the contribution of the stimulus-driven binaural masking release plays a minor role while binaural stream segregation and the availability of glimpses in the better ear had a stronger influence on improving the speech intelligibility.

A Study on the Reference Values and Cutoff Criteria of Masking Level Difference for Children Aged 7–12 Years

“…Binaural interaction is an auditory ability characterized by the processing of sounds, which may or may not be complementary, presented binaurally. By allowing the fusion of such stimuli in a single acoustic event, this skill facilitates tasks such as sound localization, hearing in noise, and hearing with competitive stimuli [5,6]. One of the main markers of the integrity of binaural interaction is the presence of a phenomenon known as release from masking, which was firstly described by two simultaneous studies conducted with tonal [7] and verbal [8] stimuli accompanied by noise.…”

Masking Level Difference: avaliação da confiabilidade teste-reteste em estudantes universitárias normo-ouvintes

“…Esta melhora caracteriza o fenômeno de liberação do mascaramento, que pode ser quantificado por meio da diferença entre os limiares obtidos nas condições homofásica e antifásica, denominada MLD (6,7) . Essa liberação pode contribuir para uma melhor compreensão da fala em situações de ruído competitivo ou na presença de vários falantes, uma vez que há melhora da percepção do sinal quando as diferenças entre as pistas binaurais do sinal e do mascaramento aparecem simultaneamente no tempo (8) .…”