ACOUSTIC ANALYSIS OF DYSARTHRIA ASSOCIATED WITH MULTIPLE-SCLEROSIS

Approximately 40% of all individuals with multiple sclerosis (MS) pres ent some degree of speech impairment. MS speakers with dysarthria are a heterogeneous group and the speech disorder is characterized by dist urbances of the temporal patterning of speech as well as articulatory and phonatory symptoms. Previous research also indicates that the neur omotor dysfunction manifests itself in the fundamental frequency of su stained phonation, even in the absence of other speech symptoms: The p resent study was designed with the specific purpose of exploring the t emporal, spectral and phonatory acoustic features of five MS speakers as compared to those of two normal controls. It was found that the dys arthric symptoms of these MS speakers largely mirror their different u nderlying neuromotor dysfunctions, and that they exhibit temporal and articulatory deviation when compared to the normal speakers. It is als o suggested that a Fourier spectrum analysis of the derived pitch of t he sustained phonation in MS speakers is particularly valuable in char acterizing an important but often subtle symptom of their illness.