Improvement of Continuous Dysarthric Speech Quality

Dysarthria refers to a group of motor speech disorders as the result of any neurological injury to the speech production system. Dysarthric speech is characterised by poor speech articulation, resulting in degradation in speech quality. Hence, it is important to correct or improve dysarthric speech so as to enable people having dysarthria to communicate better. The aim of this paper is to improve the quality of continuous speech of several people suffering from dysarthria. Experiments in the current work use two databasesNemours database and speech data collected from a dysarthric speaker of Indian origin. Durational analysis of dysarthric speech versus normal speech is performed. Based on the analysis, manual modifications are made directly to the speech waveforms and an automatic technique is developed for the same. Evaluation tests indicate an average preference of 78.44% and 67.04% for the manually and automatically altered speech over the original dysarthric speech, thus emphasising the effect of durational modifications on the perception of speech quality. Intelligibility of speech generated by three techniques, namely, proposed automatic modification technique, a formant re-synthesis technique, and an HMMbased adaptive system, is compared.