Table 1.
Speech stimuli.
Figure 1.
Baseline measures of /s/ and /∫/ production and perception.
A. Boxplots of /s/ and /∫/ productions for individual subjects in each group. For visualization purposes, centroid values were normalized by subtracting the mean /s/-centroid frequency on an individual basis, and the subjects within each group were sorted on the basis of the magnitude of the production contrast. B. Mean /s-∫/ identification functions (sigmoid) for each group. C. Mean slope parameter values for the sigmoid-functions fit to each subject's pattern of responses in the phoneme identification task. Error bars show one standard error of the mean.
Figure 2.
Changes in /s/-centroid frequency.
A. Individual changes in centroid frequency within the adult (top panel) and child (bottom panel) groups. Changes are computed as the difference between the baseline phase and the end of the speech practice phase under conditions of altered auditory feedback. For visualization purposes, subjects are sorted on the basis of effect size. B. Group-mean change in /s/-centroid following speech practice under conditions of altered auditory feedback. Error bars show one standard error of the mean.
Figure 3.
Shift in perceptual boundary for each subject.
The figure shows the change in perceptual boundary following the period of speech practice (post-test – pretest), computed on the basis of individually estimated phoneme identification functions.
Figure 4.
Change in perceptual boundary location.
A. Mean change in perceptual boundary location for each group (post-test - pretest). B. Mean magnitude of the perceptual boundary effect for each group, irrespective of the direction of shift (averaging across absolute values of the perceptual boundary shift for each subject). Error bars show one standard error of the mean.