Temporal acoustic measures of dysarthria associated with amyotrophic lateral sclerosis

The purpose of this study was to investigate stop-gap duration, voice onset time (VOT), and vowel duration in intelligible speakers with amyotrophic lateral sclerosis (ALS). Broadband sound spectrograms were used to measure 8 normal and 8 ALS speakers' intelligible speech productions of monosyllabic words containing word-initial stop-plosive consonants (/p, t, k, b, d, g/). Significant differences were found between the two groups for both vowel duration and stop-gap duration; moreover, correlational analysis indicated that the ALS speakers, as a group, exhibited a direct relationship between stop-gap and vowel durations associated with productions of /t/ and /k/. No significant differences were found between the two talker groups for VOT. Results will be related to the neuroanatomical and physiological mechanisms involved in dysarthric (ALS) speech.