Assessment on impact of various types of dysarthria on acoustic parameters of speech

Abstract

Dysarthria is one of the major speech impairments that makes speech unintelligible and inaudible. It is a motor speech disorder which occurs due to neurological injury to the motor-speech system and an indication of this is a poor articulation of phonemes. Dysarthria can be of different types: spastic, flaccid, hypokinetic, hyperkinetic, ataxia, mixed etc. Studying the effect of different types of dysarthria on speech, using signal processing techniques is a largely unexplored area. The fundamental frequency, formant frequency and energy of the speech signal are information bearing acoustic parameters of speech. This paper summarizes the impact of spastic, flaccid and hypokinetic types of dysarthria on the above listed acoustic parameters of speech. These parameters are compared with similar parameters for normal speech. A comparison shows that the acoustic parameters of normal speech and impaired speech are very different. By modifying these parameters of impaired speech, the researchers hope to enhance dysarthria affected speech, to make it resemble normal speech as closely as possible.