Acoustic analysis of amyotrophic lateral sclerosis speech

Abstract

Seventeen victims of amyotrophic lateral sclerosis (ALS), were recorded as they produced /p t k b d g/ in a CVC syllable embedded in a carrier phrase. The duration of the stop consonant closure period, the release burst, and the aspirated phase of each of the stops, as well as the total duration of all pre‐ and post‐stop vowels was determined spectrographically. In general, the ALS speakers produced highly varied speech which included numerous instances of voicing throughout voiceless segments, frication of voiced and voiceless stops, and multiple release bursts. Comparisons of group mean durations, to those of normal speakers, indicates that the effects of decreased speaking rate in ALS are not evenly distributed across segments or portions of segments. Instead, some segment durations in ALS speech remain within normal limits while others increase relative to those seen in normal speech. Thus, the most sensitive acoustic/articulatory measure of the speech deterioration associated with ALS is achieved by comparing two or more durational measures with speakers. [Work supported by Kansas City Regional ALS Research Center, and NIH.]