Perceptual assessment of contrastive voicing in 2-year-old children’s speech by adult and school-age child listeners

Abstract

Past research assessing perception of voice onset time (VOT) in stops suggests that perceptual acuity improves as a function of age, with adults showing steeper labeling functions and narrower boundary widths. Most work has used synthetic stimuli varying a single acoustic cue, so extending such findings to natural speech may not be straightforward. Perceptual judgments may also be influenced by distributional properties of the dataset, e.g., VOT distributions along a continuum and/or the number of productions in each VOT category. This study will assess how distributional characteristics of naturally produced child speech stimuli, collected from six 2–3-year-old English-speaking children, might influence adult and child labeling behavior. Six exemplars per child were chosen with short-lag /b d/, short-lag /p t/, long-lag /b d/, long-lag /p t/. For each POA and VOT group, /b d/ and /p t/ VOTs were bimodally distributed (shorter for voiced targets), separated by a 5 ms gap. We will seek listening data from 20 adults and 20 children (aged 6–8). We anticipate high and similar accuracy levels for both groups when VOT values are appropriate for the target, but clearer group differences for inappropriate VOTs.