Additivity of Auditory Masking

This project implements a formal methodology for studying and modeling the auditory processes involved in the detection of signals in the presence of complex masking sounds. This method, termed the "measurement approach", consists of the following components: Signal threshold is obtained in the presence two or more simple maskers (tones or noise bands) individually and in various combinations. The maskers might be separated in frequency, in time, or in both frequency and time. An attempt is then made to predict the combined effect of the maskers from the individual effects of the maskers, using basic axioms of Measurement Theory (Coombs, Dawes, and Tversky, 1970). Specifically, mathematical transformations are sought whereby the combined masking effects can be related to the individual effects by addition. The rationale underlying this "measurement approach" is that the mathematical transformations, if they exist, may be used like a model, to summarize the results of past experiments, to predict the results of future experiments, and to shed light on the nature of the mechanisms underlying masking by complex sounds.

Selected Publications

Lutfi, R. A. (1983a). Additivity of simultaneous masking. Journal of the Acoustical Society of America, 73, 262-267. * Lutfi, R. A. (1983b). Simultaneous masking and unmasking with bandlimited noise. Journal of the Acoustical Society of America, 73, 899-905. * Lutfi, R. A. (1984). Predicting frequency selectivity in forward masking from simultaneous masking. Journal of the Acoustical Society of America, 76, 1045-1050. * Lutfi, R. A. (1985a). A power-law transformation predicting masking by sounds with complex spectra. Journal of the Acoustical Society of America, 77, 2128-2136. * Lutfi, R. A. (1985b). A reply to Dr. B. C. J. Moore [Journal of the Acoustical Society of America, 78, 253-255 (1985)]. Journal of the Acoustical Society of America, 78, 255-257. * Lutfi, R. A. (1986). Two- versus four-tone masking, revisited. Journal of the Acoustical Society of America, 80, 422-428. * Weber, D. A., & Lutfi, R. A. (1986). The unimportance of suppression. Auditory Frequency Selectivity, A NATO Advanced Workshop, B. C. J. Moore & R. D. Patterson, (eds.) Plenum: New York. * Lutfi, R. A. (1987). Masking additivity in the hearing-impaired. Hearing Research, 25, 3-10. * Lutfi, R. A. (1988a). Interpreting measures of frequency selectivity: Is forward masking special? Journal of the Acoustical Society of America, 83, 163- 177. * Lutfi, R. A. (1988b). Complex interactions between pairs of forward maskers. Hearing Research, 35, 71-78. * Lutfi, R. A. (1990b). How much masking is informational masking? Journal of the Acoustical Society of America, 88, 2607-2610.