Training away the phonemic restoration illusion

Abstract

Phonemic restoration is an auditory illusion which arises when a phoneme is removed from a word and replaced with noise. Listeners hear the word as intact: they perceptual]y restore the missing phoneneme. Recently it has been shown that the magnitude of the illusion diminishes with practice [H. C. Nusbaum, A. C. Walley, T. D. Carrell, and W. H. Resslar, Res. on Speech and Hearing Prog. Rep. No. 8, Indiana University (1983)]. One explanation for this result is that subjects learn to ignore their expectation of hearing an intact word by directing attention to the speech waveform itself, specifically attending to the location of the target phoneme. To test this explanation, two groups of subjects received training in the illusion. Group 1 (Control) saw each stimulus word printed on a CRT screen prior to hearing that word. Group 2 (Directed Attention) also saw each word on the screen, but with the target phoneme underlined in each. The performance of the second group relative to the first has implications both for an explanation of the illusion as a misdirector of attention, as well as for theories of the role of attention and the degree to which it may be controlled in the perception of fluent speech.