Comparison of speaking rate, articulation rate and alternating motion rate in dysarthric speakers.

Despite recent indications that speaking rate, articulation rate and alternating motion rate (AMR) are sensitive to the influence of neurological disease on speech production in dysarthric speakers, the relationship among these parameters remains largely questionable. In the current study, speech samples were collected from 62 dysarthric speakers and 34 controls while reading a passage. Acoustic analysis investigated speaking rate, articulation rate and AMR and compared these parameters between the dysarthric and control groups and within the control and dysarthric group. The major findings were: (1) Speaking rate, articulation rate and AMR were all markedly lower in dysarthric speakers than in controls. (2) Marked correlations were recognized between speaking rate, articulation rate and AMR in the dysarthric group. (3) Compared with the speaking rate and articulation rate, AMR is characterized as follows: (i) variation was more limited in controls, and (ii) the control group was clearly distinguishable from the dysarthric group. (4) Unlike in controls, AMR in the dysarthric speakers was notably lower than their articulation rate. We therefore conclude that AMR is a more easily detected sign of abnormal articulation than speaking rate and articulation rate. Copyright (c) 2006 S. Karger AG, Basel.