Perceptual restoration of a “missing” speech sound: Auditory induction or illusion?

Abstract

This study investigated whether the apparent completeness of the acoustic speech signal during phonemic restoration derives from a process of auditory induction (Warren, 1984) or segregation, or whether it is an auditory illusion that accompanies the completion of an abstract phonological representation. Specifically,five experiments tested the prediction of the auditory induction (segregation) hypothesis that active perceptual restoration of an [s] noise that has been replaced with an extraneous noise would use up a portion ofthat noise's high-frequency energy and consequently change the perceived pitch (timbre, brightness) of the extraneous noise. Listeners were required to compare the pitch of a target noise, which replaced a fricative noise in a sentence, with that of a probe noise preceding or following the speech. In the first two experiments, a significant tendency was found in favor of the auditory induction hypothesis, although the effect was small and may have been caused by variations in acoustic context. In the following three experiments, a larger variety of stimuli were used and context was controlled more carefully; this yielded negative results. Phoneme identification responses collected in the same experiments, as well as informal observations about the quality of the restored phoneme, suggested that restoration of a fricative phone distinct from the extraneous noise did not occur; rather, the spectrum of the extraneous noise itself influenced phoneme identification. These results suggest that the apparent auditory restoration which accompanies phonemic restoration is illusory, and that the schemaguided process of phoneme restoration does not interact with auditory processing.

Accenting and detection of timing variations in tone sequences: Different kinds of accents have different effects

“…Reduced sensitivity has been observed for the presence or absence of phonemes and tones masked by noise when they were incorporated in words and chords, respectively (DeWitt & Samuel, 1990;Samuel, 1981). This explanation implies that listeners respond to a more abstract sense of grouping in the stimulus, rather than comparing stimuli in terms of exactly how long the IOIs were heard, which is similar to Repp's (1992a) interpretation that, in phonemic restoration, the restored phonemes are not necessarily "heard" as sounds but their mental representations are activated.…”

Auditory induction: Reciprocal changes in alternating sounds

“…He hypothesized that no reallocation of auditory input from extraneous noise to speech occurs when speech is restored (although he believes that such reallocation does occur with nonverbal induction). Since all of the prior studies dealing with phonemic restorations were concerned with changes involving the speech signal and not the noise, Repp (1992) attempted to determine whether or not perceptual changes occurred in the noise. He replaced the phoneme lsi in a word with a noise having a different spectral proftle from that of the hiss corresponding to the pho- neme, and investigated whether or not listeners heard a change in the timbre or brightness (not the loudness) of the interpolated noise when it was used to restore the /s/.…”

Dynamic cortical representations of perceptual filling-in for missing acoustic rhythm

“…Our method subscribes to the latter approach, also referred to as 'filling-in', which emphasizes the signal detection strategy followed in cases where a listener classification is inconsistent with the token absence in a gap 3,[23][24][25][26][27][28][29] . As has been noted 30 , from the listener's utilitarian perspective, this effect of induction in a challenging environment is not aimed at the production of decision errors (or illusions) but to assist against masking. Restoration refers to the perception .…”