Perceptual learning of phonetic information that indicates morphological structure

Familiarity with a talker or accent can facilitate speech perception, but little is known about the acoustic-phonetic knowledge that is acquired during exposure to an unfamiliar talker, particularly with respect to how a talker realises grammatical and prosodic distinctions. The present experiment used relatively natural stimuli and tasks to investigate listeners' adaptation to a phonetic variant that is systematically associated with a morphological context, specifically the English /ri:/ prefix. Results showed that listeners who had previously been exposed to the atypical variant in /ri:/ prefixes in stories scored higher than control listeners in an intelligibility-in-noise task that included instances of the atypical variant. Perceptual learning was partly specific to the /ri:/ prefix, though there was weak generalisation of learning to word-initial /ri:/ syllables that were not prefixes. These results emphasise the value of developing context-sensitive, probabilistic models of speech perception which include multiple, parallel levels of representation.