Talker-specific influences on phonetic category structure.

Area of Science:

• Psycholinguistics
• Auditory Neuroscience
• Speech Communication

Background:

• Speech perception models aim to explain how listeners achieve comprehension despite acoustic signal variability.
• Listeners use categorical perception and lexical information to adapt to talker-specific phonetic variations.
• Existing research suggests listeners can modify category boundaries based on talker-specific productions.

Purpose of the Study:

• To investigate perceptual learning of talker-specific phonetic differences.
• To examine how listeners adjust internal category structure and category boundaries when exposed to novel talker productions.
• To determine the constraints on functional plasticity in speech perception.

Main Methods:

• Utilized speech synthesis to manipulate talker productions of the stop voicing contrast.
• Exposed two listener groups to distinct talker voice characteristics.
• Assessed internal category structure and category boundary shifts post-exposure.

Main Results:

• Listeners dynamically adjusted their internal category structure to align with the experienced talker's voice.
• The phonetic category boundary remained fixed, showing resistance to change.
• These effects were observed for both trained and novel lexical items.

Conclusions:

• Findings indicate input-driven constraints on functional plasticity in the language architecture.
• Listeners maintain stable linguistic knowledge while exhibiting flexible phonetic representations.
• Dynamic adjustment of internal category structure supports robust speech comprehension across talkers.