Prosodic Analysis and Enhancement of Dysarthric Speech

Abstract

Dysarthria is a disorder that is caused in the nervous system. It is caused by damage in some parts of the brain such as cerebellum. Because of the damage in brain it causes weakness in muscles used for speech therefore it happens as in mumbled, slurred or slow speech that human and the machine find it difficult to understand such slurred speech. The Automatic Speech Recognizers which were designed for speech intelligibility perform poorly on dysarthric speech recognition. This paper focuses on the transformation of voice for dysarthria to enhance its intelligibility Formant tracking, pitch and energy estimation with durational cues from dysarthric speech facilitate the modification of these trajectories to more closely approximate the desired intelligible target speech. The transformation of the speech is done by using formant re-synthesis, pitch change and duration morphing. The results of such transformation results indicate that the transformation of the pitch and duration step enhances the intelligibility of dysarthric speech and make it easy to understand for humans and machines.