Adaptive Plasticity in Perceiving Speech Sounds

Listeners can rely on perceptual learning and recalibration in order to make reliable interpretations during speech perception. Lexical and audiovisual (or speech-read) information can disambiguate the incoming auditory signal when it is unclear, due to speaker-related characteristics, such as an unfamiliar accent, or due to environmental factors, such as noise. With experience, listeners can learn to adjust boundaries between phoneme categories as a means of adaptation to such inconsistencies. Recalibration experiments tend to use a targeted approach by embedding ambiguous phonemes into speech or speechlike items, and with continuous exposure, a learning effect can be induced in listeners, wherein disambiguating contextual information shifts the perceived identity of the same ambiguous sound. The following chapter will review current and past literature regarding lexical and audiovisual influences on phoneme boundary recalibration, as well as theories and neuroimaging data that potentially reveal what facilitates this perceptual plasticity.keywordsrecalibrationperceptual learningspeech perceptionphonetic processinglexical processingaudiovisual speechspeech-reading