Release from masking through ipsilateral and contralateral comodulation of a flanking band

Abstract

Part of the masking of a tone by noise accrues from the difficulty of evaluating the mean increment in power during the observation interval, in relation to the distribution of power fluctuations in random noise. This decision theory model of detection must now be developed to encompass an estimation and correction procedure for noise envelope fluctuations defined by critical bands other than those containing the signal. As shown by Hall et al. [J. Acoust. Soc. Am. 76, 50–56 (1984)], presence of common envelope fluctuations in two separate noise bands can permit the signal in one to be released from masking by 2 to 10 dB, depending on the stimulus parameters. The estimation and correction process seems to occur at more than one stage in the auditory system, as we find a release from masking with contralateral as well as ipsilateral presentation of the flanking band. The magnitude of the contralateral effect is not as large as the ipsilateral effect.