Acoustic features for identifying constitutions in traditional Chinese medicine.

OBJECTIVES: Constitutions are Traditional Chinese Medicine syndromes that are used to classify symptoms. The present study sought to identify objective acoustic features for eight commonly occurring abnormal constitutions. METHODS: Speech signals were obtained from 281 subjects through a 1-second vowel sound, /a/, uttered by the subjects. For each constitution, differences in acoustic parameters between the low-score and high-score groups were compared. RESULTS: Subjects in the high-score groups for Yin-deficiency, Qi-deficiency, Phlegm-wet, Blood-stasis, and Qi-depression showed lower acoustic intensities than subjects in the corresponding low-score groups (all p<0.05). Subjects in the high-score groups of Qi-deficiency and Blood-stasis exhibited higher maximum pitches and higher minimum pitches than subjects in the low-score groups (all p<0.01). The average number of zero-crossings was lower in the high-score groups of Qi-deficiency and Blood-stasis than in the low-score groups for both constitutions (p<0.05). Subjects in the high-score group of special diathesis demonstrated higher low-spectral-energy ratios than subjects in the low-score group (p<0.05), and subjects in the high-score group of Blood-stasis had higher middle spectral energy ratios than subjects in the low-score group (p<0.05). In contrast, the middle spectral energy ratio in the high-score group of special diathesis was lower than in its corresponding low-score group (p<0.05). The high spectral energy ratios were lower in the high-score groups for Yin-deficiency and Blood-stasis (both p<0.05) than in the low-score groups. CONCLUSIONS: The present study identified acoustic features for constitutions and established objective methods for constitutional diagnosis. These acoustic features can potentially be applied in the expert system of Traditional Chinese Medicine for the diagnosis of constitutions in the general population.