Acoustic and Perceptual Analyses of Adductor Spasmodic Dysphonia in Mandarin-speaking Chinese.

OBJECTIVE: The objective of this study was to examine the perceptual structure and acoustic characteristics of speech of patients with adductor spasmodic dysphonia (ADSD) in Mandarin. STUDY DESIGN: Case-Control Study MATERIALS AND METHODS: For the estimation of dysphonia level, perceptual and acoustic analysis were used for patients with ADSD (N = 20) and the control group (N = 20) that are Mandarin-Chinese speakers. For both subgroups, a sustained vowel and connected speech samples were obtained. The difference of perceptual and acoustic parameters between the two subgroups was assessed and analyzed. RESULTS: For acoustic assessment, the percentage of phonatory breaks (PBs) of connected reading and the percentage of aperiodic segments and frequency shifts (FS) of vowel and reading in patients with ADSD were significantly worse than controls, the mean harmonics-to-noise ratio and the fundamental frequency standard deviation of vowel as well. For perceptual evaluation, the rating of speech and vowel in patients with ADSD are significantly higher than controls. The percentage of aberrant acoustic events (PB, frequency shift, and aperiodic segment) and the fundamental frequency standard deviation and mean harmonics-to-noise ratio were significantly correlated with the perceptual rating in the vowel and reading productions. CONCLUSIONS: The perceptual and acoustic parameters of connected vowel and reading in patients with ADSD are worse than those in normal controls, and could validly and reliably estimate dysphonia of ADSD in Mandarin-speaking Chinese.