No evidence for a benefit from masker harmonicity in the perception of speech in noise

Release from same-talker speech-in-speech masking: Effects of masker intelligibility and other contributing factorsa)

Human speech perception declines in the presence of masking speech, particularly when the masker is intelligible and acoustically similar to the target. A prior investigation demonstrated a substantial reduction in masking when the intelligibility of competing speech was reduced by corrupting voiced segments with noise [Huo, Sun, Fogerty, and Tang (2023), "Quantifying informational masking due to masker intelligibility in same-talker speech-in-speech perception," in Interspeech 2023, pp. 1783-1787]. As this processing also reduced the prominence of voiced segments, it was unclear whether the unmasking was due to reduced linguistic content, acoustic similarity, or both. The current study compared the masking of original competing speech (high intelligibility) to competing speech with time reversal of voiced segments (VS-reversed, low intelligibility) at various target-to-masker ratios. Modeling results demonstrated similar energetic masking between the two maskers. However, intelligibility of the target speech was considerably better with the VS-reversed masker compared to the original masker, likely due to the reduced linguistic content. Further corrupting the masker's voiced segments resulted in additional release from masking. Acoustic analyses showed that the portion of target voiced segments overlapping with masker voiced segments and the similarity between target and masker overlapped voiced segments impacted listeners' speech recognition. Evidence also suggested modulation masking in the spectro-temporal domain interferes with listeners' ability to glimpse the target.

In-channel cancellation: A model of early auditory processing

A model of early auditory processing is proposed in which each peripheral channel is processed by a delay-and-subtract cancellation filter, tuned independently for each channel with a criterion of minimum power. For a channel dominated by a pure tone or a resolved partial of a complex tone, the optimal delay is its period. For a channel responding to harmonically related partials, the optimal delay is their common fundamental period. Each peripheral channel is thus split into two subchannels-one that is cancellation-filtered and the other that is not. Perception can involve either or both, depending on the task. The model is illustrated by applying it to the masking asymmetry between pure tones and narrowband noise: a noise target masked by a tone is more easily detectable than a tone target masked by noise. The model is one of a wider class of models, monaural or binaural, that cancel irrelevant stimulus dimensions to attain invariance to competing sources. Similar to occlusion in the visual domain, cancellation yields sensory evidence that is incomplete, thus requiring Bayesian inference of an internal model of the world along the lines of Helmholtz's doctrine of unconscious inference.