Determining Predictors of Acquisition for /r/ Using Acoustic Signal Processing

This longitudinal study aimed to determine whether significant differences existed between the baseline inaccurate signals of the /r/ phoneme for children that eventually acquire or do not acquire /r/. Seventeen participants ages 5-8 who had not acquired /r/ in any of its allophonic contexts were recorded approximately every 3 months from the age of recruitment until they either acquired /r/ in conversation (80% accuracy) or turned eight years old. The recorded audio files were trimmed and labelled using Praat, and signal processing was used to compare initial and final recordings of three allophonic variations of /r/ (vocalic, prevocalic, postvocalic) for each participant. Differences were described using Mel-log Spectral plots. For each age group, initial recordings of participants that eventually acquired /r/ were compared to those of participants that did not acquire /r/. Participants that had not acquired /r/ and had yet to turn eight years old were compared by whether they were perceived to be improving or perceived not to be improving. Significant differences in Mel-log spectral plots will be discussed, and the implications of baseline differences will be highlighted, specifically with respect to the feasibility of identifying predictive markers for acquisition
on-acquisition of the difficult /r/ phoneme.