An articulatory model with developmental constraints: Some evidence from child speech data

In this paper, we quantitatively investigate the mechanism of children's deviations from adult articulation (CDFA) by using an articulation control model. The target CDFA is the substitution of /sh/ for /s/ and /n/ for /d/ at the beginning of words or after prolonged sounds, and the substitution of /r/ for /d/ in the middle of words. Our analysis shows that the CDFA at the beginning of words can be simulated by slowing the movement of the tongue. Moreover, it is shown that the CDFA is caused by the constraints that minimize the movement distance and the curvature at triplet points whose center is the target sound in the tongue-related parameter space