The information-divergence hypothesis of informational masking

Abstract

In recent years there has been growing interest in masking that cannot be attributed to interactions in the cochlea-so--called informational masking (IM). Similarity in the acoustic properties of target and masker and uncertainty regarding the masker are the two major factors identified with IM. These factors involve quite different manipulations of signals and are believed to entail fundamentally different processes resulting in IM. Here, however, evidence is presented that these factors affect IM through their mutual influence on a single factor-the information divergence of target and masker given by Simpson-Fitter's da [Lutfi et al. (2012). J. Acoust. Soc. Am. 132, EL109-113]. Four experiments are described involving multitone pattern discrimination, multi-talker word recognition, sound-source identification, and sound localization. In each case standard manipulations of masker uncertainty and target-masker similarity (including the covariation of target-masker frequencies) are found to have the same effect on performance provided they produce the same change in da. The function relating d(') performance to da, moreover, appears to be linear with constant slope across listeners. The overriding dependence of IM on da is taken to reflect a general principle of perception that exploits differences in the statistical structure of signals to separate figure from ground.

Release from informational masking by auditory stream segregation: perception and its neural correlate

“…Recently, Lutfi et al . () proposed an alternative analysis approach based on the Kullback–Leibler divergence. This approach, however, was not suited for our dataset as the sample size of our neuronal data was not sufficient for all stimulus conditions to successfully apply such an analysis.…”

Auditory streaming of tones of uncertain frequency, level, and duration

“…1 (Lutfi, 1993;Lutfi et al, 2013). These predictions are based on the premise that masking is a linear function of the statistical separation (relative entropy) of target and masker and that streaming is linked to a release from masking.…”

“…For all experimental conditions, the stimuli were ABA-ABA tone sequences identical to those of past streaming studies with one exception: The sequences were made uncertain by drawing the frequency, level, or duration of the tones independently and at random from normal distributions of these parameters, similar to what has been done in past masking studies (e.g., Lutfi, 1992Lutfi, , 1993Lutfi et al, 2013). The standard deviation r of the distributions was fixed within a block of trials but varied across blocks over a maximum realistic range consistent with past masking studies.…”

“…The model applied in this case was the component-relative-entropy (CoRE) model, which has been widely applied to studies of informational masking [see Lutfi (1993) and Lutfi et al (2013) for reviews]. The model predicts that the masking of stimulus A by stimulus B, and so streaming by our premise, is related to the degree to which average statistical properties of A and B differ (their information divergence or relative entropy).…”

“…These later sounds differ in significant ways from those of streaming studies, but perhaps the most important difference is that they vary unpredictably from one moment to the next. This is important because stimulus uncertainty is identified as one of most significant factors affecting performance in the studies using these sounds (Kidd et al, 2008;Lutfi et al, 2013;Ellis, 1996). The effect of stimulus uncertainty on streaming thus has implications for how streaming is to be considered in relation to this previous work.…”