Recalibration of Phonetic Categories by Lipread Speech: Measuring Aftereffects After a 24-hour Delay

Tilburg University, Dept. of Psychology, Tilburg, The Netherlands.
Language and Speech (Impact Factor: 1.04). 02/2009; 52(Pt 2-3):341-50. DOI: 10.1177/0023830909103178
Source: PubMed


Listeners hearing an ambiguous speech sound flexibly adjust their phonetic categories in accordance with lipread information telling what the phoneme should be (recalibration). Here, we tested the stability of lipread-induced recalibration over time. Listeners were exposed to an ambiguous sound halfway between /t/ and /p/ that was dubbed onto a face articulating either /t/ or /p/. When tested immediately, listeners exposed to lipread /t/ were more likely to categorize the ambiguous sound as /t/ than listeners exposed to /p/. This aftereffect dissipated quickly with prolonged testing and did not reappear after a 24-hour delay. Recalibration of phonetic categories is thus a fragile phenomenon.

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    • "They found that despite large immediate effects, learning dissipated quickly and did not return after a 24-h delay. This comparison may be qualified by the fact that Eisner and McQueen (2006) tested fricatives in their lexically driven perceptual learning study, whereas Vroomen and Baart (2009b) used stops. Although the findings of Vroomen et al. (2004; Vroomen et al., 2007) and of Vroomen and Baart (2009b) for audiovisual recalibration are in contrast to what has been found with lexically induced learning of fricatives, the direct comparison of the two kinds of learning (van Linden & Vroomen, 2007) found more similarities than differences. "
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