A Novel Approach for Intelligibility Assessment in Dysarthric Subjects

Dysarthria is a motor speech impairment caused by muscle weakness. Individuals, with this condition, are unable to control rapid movement of the velum leading to reduction in intelligibility, audibility, naturalness and efficiency of vocal communication. Systems that can assess intelligibility of dysarthric speech can help clinicians diagnose the impact of therapy and medication. In the paper, we propose a usable novel method to assess intelligibility of dysarthric speakers. The approach is based on the observation that the performance of a speech recognition engine deteriorates with increase in severity of the disorder. The mismatch between the original word and the recognized string is exploited to compute the dysarthria intelligibility score. Experiments on UA speech corpus show that the computed intelligibility score exhibits a significant correlation with perceptually assessed intelligibility scores. We further show that a small set of words spoken by the dysarthric subject is sufficient to assess the speech intelligibility reliably.