Forward masking has been demonstrated in the amplitude-modulation (AM) domain [M. Wojtczak and N. F. Viemeister, J. Acoust. Soc. Am. 118, (2005)] for masker and signal imposed on the same carrier. This study explores an effect of AM on detection of AM imposed sequentially on a different carrier. Data show that a 40-Hz AM (interferer) imposed on a 2-kHz carrier affects detection of a 40-Hz AM (signal) imposed on a 5.5-kHz carrier after the offset of the interferer AM. The effect is analogous (and similar in size for the shortest interferer-signal delays) to modulation detection interference for simultaneous interferer AM. In another condition, two independent noise samples were presented to opposite ears. In one ear, a 40-Hz masker AM was imposed on the carrier. In the opposite ear, a 40-Hz signal was imposed on the carrier after the offset of the masker modulation. A forward-masking effect similar to but smaller in size than that in monaural presentation was observed. The data from both experiments suggest that the forward-masking effect in the modulation domain occurs at central stages of processing, where information is combined across peripheral channels and where binaural interactions occur [Supported by NIH grants DC00683 and DC006804].

       Wojtczak, M., Gregan, M. J., and Viemeister, N.F. (2006). Sequential amplitude-modulation interference across auditory channels and across ears. Presented at the 4th Joint Meeting of the Acoustical Society of America and the Acoustical Society of Japan.

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