Brainstem timing change in response to "da". A) Wave A of the response is plotted for trained subject S1 (red) and one control child, C4 (black), for both pre- (solid) and post- (dashed) test. The peaks chosen for Wave A are marked. B) Drop line plot of wave A latencies for all trained children (red) and the mean of control children (C, black) for both pre- (solid) and post- (open) test. The criterion for normalcy (1.6 SD later than the typically-developing mean) is plotted as a dashed line.