Effects of multi-talker noise on the acoustics of voiceless stop consonants in Parkinson's disease


This study examined the effect of increased speech intensity on stop consonant acoustics in Parkinson’s disease (PD). Acoustic analyses focused on measures of spirantization, voicing during closure, stop closure durations, and voice onset time. Ten individuals with Parkinson’s disease and ten age-matched controls were audio recorded while they read aloud words from the Distinctive Features Differences Test (DFD) during two conditions: no noise and 65 dB of multi-talker background noise. When compared to controls, the participants with PD had values that approached a significant difference for the measures related to greater percent voicing into closure (p=0.074), lower mean syllable intensity (p=0.069) and greater spirantization ratio (p=0.094). When compared to the no noise condition, the 65 dB multi-talker noise condition was associated with significant changes in voice onset time (VOT), syllable intensity, spirantization ratio and other measures. In addition, the place of stop consonant production had a significant effect on measures of closure duration, VOT, spectral skewness and other measures. These preliminary findings suggest that additional studies of the effect of changes in speech intensity on stop production in PD are warranted. The results of the present study identified several acoustic measures of stop production that may be useful in future evaluations of treatment outcome in PD.

In Proceedings of Western Interdisciplinary Student Symposium on Language Research