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In speech perception, when a primary acoustic cue (e.g., VOT) is ambiguous, listeners may increase the weight of a secondary cue (e.g., F0). In experiment 1, we compared the cue-weighting adjustment strategies across younger and older normal-hearing adults with a distributional learning paradigm. Two groups of native English listeners were exposed to voicing contrasts that were ambiguous in either VOT or F0. Additionally, listeners may access lexical information to help resolve the ambiguity in the acoustic signal. Older listeners have been reported to use lexical information to a greater degree than younger listeners. In experiment 2, using a lexically guided learning paradigm, we tested if younger and older adults differ in their use of lexical information when learning to interpret ambiguous acoustic tokens. There were four types of exposure, in which stimuli differed in lexical status (day-*tay; *doy-toy) and the acoustic ambiguity involved either only VOT or both VOT and F0. Preliminary results from younger normal-hearing, listeners showed significant speech adaptation effects, with a significant change in cue weights in distributional learning and salient lexical bias in lexically guided learning. More data will be collected from older adults to assess the extent of perceptual learning relative to younger adults.
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Speech perception in younger and older adults: Cue-weighting and contextual information
This dissertation compared speech perception across younger and older normal-hearing adults. We ask four research questions to assess acoustic cue weighting and the role of contextual information (lexical information and speaking rate) in speech perception. Experiment 1 tested for age-related changes in cue-weighting. The absolute weights showed that older listeners relied on both VOT and F0 more than younger listeners, and some listeners’ reliance on VOT correlated with inhibitory control when perceiving the /d/-/t/ contrast. The relative weights suggested that older listeners relied on VOT less and F0 more than younger listeners. Experiment 2 tested whether younger and older listeners used different cue-weighting adjustment strategies in distributional learning. Both older and younger listeners adjusted their reliance on acoustic cues when the primary acoustic cue (VOT) became ambiguous. Older listeners adjusted F0 to a greater degree than younger listeners, while younger listeners adjusted VOT more than older listeners. With a lexically-guided learning paradigm, Experiment 3 explored if younger and older adults differed in their use of lexical information when learning to map acoustic tokens that were ambiguous. Older and younger listeners utilized the lexical context to the same extent. In Experiment 4, the contextual effect of speaking rate was examined by embedding voicing contrasts in short and long syllables and presenting these syllables to younger and older listeners. Older and younger listeners compensated for variation in speaking rate in a similar manner as younger listeners. The findings in perceptual learning demonstrate perceptual flexibility among normal-hearing older listeners, despite an assumed decline in temporal processing.
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- Award ID(s):
- 2141302
- PAR ID:
- 10660580
- Publisher / Repository:
- Proquest
- Date Published:
- ISBN:
- 9798381426359
- Subject(s) / Keyword(s):
- speech perception cue weighting older adults VOT f0
- Format(s):
- Medium: X
- Institution:
- University of Kansas - Lawrence
- Sponsoring Org:
- National Science Foundation
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