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.

There has been growing interest in recent years in masking that appears to have its origin at a central level of the auditory nervous system—so-called informational masking (IM). Masker uncertainty and target-masker similarity have been identified as the two major factors affecting IM; however, no theoretical framework currently exists that would give precise meaning to these terms necessary to evaluate their relative importance or model their effects. The present paper offers a first attempt at such a framework constructed within the doctrines of the theory of signal detection.

Older adults are often reported in the literature to have greater difficulty than younger adults understanding speech in noise [Helfer and Wilber (1988). J. Acoust. Soc. Am, 859–893]. The poorer performance of older adults has been attributed to a general deterioration of cognitive processing, deterioration of cochlear anatomy, and/or greater difficulty segregating speech from noise. The current work used perturbation analysis [Berg (1990). J. Acoust. Soc. Am., 149–158] to provide a more specific assessment of the effect of cognitive factors on speech perception in noise. Sixteen older (age 56–79 years) and seventeen younger (age 19–30 years) adults discriminated a target vowel masked by randomly selected masker vowels immediately preceding and following the target. Relative decision weights on target and maskers resulting from the analysis revealed large individual differences across participants despite similar performance scores in many cases. On the most difficult vowel discriminations, the older adult decision weights were significantly correlated with inhibitory control (Color Word Interference test) and pure-tone threshold averages (PTA). Young adult decision weights were not correlated with any measures of peripheral (PTA) or central function (inhibition or working memory).

Research on children with Autism Spectrum Disorders suggests differences from neurotypical children in the preference for ‘social’ versus ‘nonsocial’ sounds. Conclusions have been based largely on the use of head-turn methodology which has various limitations as a means of establishing auditory preference. In the present study, preference was assessed by measuring the frequency with which children pressed a button to hear different sounds using an interactive toy. Contrary to prior results, both groups displayed a strong preference for the highly social sounds. These findings have implications for approaches to language intervention and for theoretical debates regarding social motivation.

A general finding of psychoacoustic studies is that detectability d' of a noisy signal grows less than optimally with the number N of independent observations of the signal. Competing accounts implicate internal noise common to all observations or nonoptimal decision weights given to observations. A discriminant analysis of listeners' trial-by-trial responses in a multitone level-discrimination task favored the latter account.