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Published on: April 19, 2017
Infants are sensitive to within-category variation in speech perception
Bob McMurray1, Richard N Aslin
1Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627, USA. bob-mcmurray@uiowa.edu
Infants show sensitivity to subtle speech variations, similar to adults. This research indicates that even young babies can perceive fine details within phonetic categories, impacting speech perception and learning.
Area of Science:
- Developmental Psychology
- Linguistics
- Cognitive Science
Background:
- Speech perception was traditionally viewed as categorical, with limited sensitivity to within-phoneme variations.
- Recent studies reveal adults' systematic sensitivity to within-category phonetic variation.
- Emerging evidence suggests infants may also utilize within-category variation for speech segmentation and category learning.
Purpose of the Study:
- To investigate 8-month-old infants' sensitivity to within-category phonetic variation.
- To directly examine infants' ability to perceive fine-grained acoustic differences in speech.
- To compare infant speech perception with adult capabilities regarding phonetic detail.
Main Methods:
- Two studies employed the head-turn preference procedure with 8-month-old infants.
- Infants were exposed to repeated tokens of words starting with /b/ or /p/.
- Listening times were measured for variations within the same phonetic category and for cross-category tokens.
Main Results:
- Infants demonstrated significantly different listening times for within-category variations compared to original tokens.
- Infants also showed differential listening times between within-category variations and cross-category competitors.
- Results indicate infants' systematic sensitivity to fine-grained phonetic detail.
Conclusions:
- Eight-month-old infants, like adults, are sensitive to subtle, within-category variations in speech.
- This sensitivity suggests a more nuanced perception of phonetic categories in early development.
- Infants' ability to process fine phonetic detail has implications for speech perception and language acquisition models.
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