Masking release for gap detection.
In random noise, masking is influenced almost entirely by noise components in a narrow band around the signal frequency. However, when the noise is not random, but has a modulation pattern which is coherent across frequency, noise components relatively remote from the signal frequency can actually produce a release from masking. This masking release has been called comodulation masking release (CMR). The present research investigated whether a similar release from masking occurs in the analysis of a suprathreshold signal. Specifically, the ability to detect the presence of a temporal gap was investigated in conditions which do and do not result in CMR for detection threshold. Similar conditions were investigated for the masking level difference (a binaural masking release phenomenon). The results indicated that suprathreshold masking release for gap detection occurred for both the masking-level difference (MLD) and for CMR. However, masking release for gap detection was generally smaller than that obtained for detection threshold. The largest gap detection masking release effects obtained corresponded to relatively low levels of stimulation, where gap detection was relatively poor.
Hall
J W
JW
Division of Otolaryngology/Head & Neck Surgery, University of North Carolina Medical School, Chapel Hill.
Grose
J H
JH
D000161:Acoustic Stimulation; D001309:Auditory Threshold / Q000502:physiology; D006801:Humans; D010470:Perceptual Masking / Q000502:physiology*; D011571:Psychoacoustics