Assessment of dysarthria in ALS patients has not been fully studied. The aim of the study was to assess a typical dysarthria profile for different ALS group. 53 patients with definite (n=27) or probable (n=26) ALS (according to WFN criteria) were studied. Each patient had three acoustic, computer-analysed tests. The following consonants and vowels: "R", "L", "D", "T", "M", "W", "P", "B", "G","K","H", "Q", "O", "U", "T" were chosen for analysis. We used the Euclidian principle for analyses of sequences of sound formants and the mean sound distances from the pattern (Δf=125 Hz, ΔT=9 ms, Δs=0.5 dB). Our study showed the occurrence of characteristic dysarthria profile in different ALS groups ie. for bulbar group: "B", "O", "I", "W", "T" and for the limb group; "B", "I", "T", "W", "O" were the most deformed. We also demonstrated that preclinical dysarthric disorders occur among the ALS limb group. This study indicated a possibility of detecting and monitoring dysarthria in ALS based on acoustic speech analysis of changes in certain sounds.

Index Terms. acoustic speech analysis, dysarthria, ALS