The coding of intensity and the interaction of forward and backward masking

Abstract

The detectability of a signal preceded and followed by noise maskers in humans is less than the prediction based on a simple addition of the effects of the maskers (i.e., an intensity sum). Data verifying and extending this finding were collected in a variety of conditions in which the 2 maskers either surrounded the signal in time or preceded it. Related claims [2] were supported; the failure of the intensity-sum argument is likely to be due to nonlinearities in the coding of intensity and the signal threshold is a monotonic measure of the internal percept a essentially the same time relative to the signal for different masking conditions. This latter result negates the integrator-movement hypothesis (which holds that the time varies) and provides important support for the chain of derivations obtained by Penner and Shiffrin.