ASA 125th Meeting Ottawa 1993 May

5aPP3. A comparison of peripheral and ``attentional'' auditory filters.

Donna L. Neff

Theresa M. Dethlefs

Walt Jesteadt

Boys Town Natl. Res. Hosp., 555 N. 30th St., Omaha, NE 68131

Robert A. Lutfi

Univ. of Wisconsin, Madison, WI 53706

The relation between peripheral and ``attentional'' filters was explored in simultaneous masking for eight normal-hearing listeners. Thresholds for a sinusoidal signal at 1000 Hz were measured as a spectral gap in a masker was progressively widened. For peripheral filters, the masker was a notched noise and a one-parameter ROEX model was used to describe filter properties. For ``attentional'' filters, the maskers were multicomponent complexes of two or ten components of random frequency content, and the ROEX model was again applied. Indices of peripheral filter width did not distinguish listeners who showed large versus small effects of masker uncertainty in the ``attentional'' filter conditions. Indices of peripheral processing efficiency, however, were poorer for listeners showing large uncertainty effects, as were measures of both the width and processing efficiency of presumed ``attentional'' filters. An alternative analysis of the ``attentional'' filter data will examine whether component entropy or relative variance [R. A. Lutfi, J. Acoust. Soc. Am. (to be published)] can account for the decline in masking observed as the spectral gap in the masker is increased. [Work supported by AFOSR and NIDCD.]