음성진전(vocal tremor) 환자들의 음향학적 특성과 예측 변인

Abstract

This paper presents the acoustic characteristics of vocal tremor (VT) to support its differential diagnosis from adductor laryngeal dystonia (ADLD) and muscle tension dysphonia (MTD) using the Motor Speech Profile (MSP) system. Vocal tremor is characterized by involuntary, low-frequency modulation of pitch and intensity, often perceptually overlapping with other voice disorders such as ADLD and MTD, which makes differential diagnosis challenging. This study analyzed sustained vowel phonation of /a/ from 67 patients diagnosed with VT, ADLD, or MTD, and extracted nine acoustic variables, primarily reflecting long-term perturbation (vF0, vAm) and tremor-related modulation (MFTR, MATR, RFTR, RATR, PFTR, PATR). Kruskal-Wallis tests revealed significant group differences in all variables except F0 and vF0. Binary logistic regression was then conducted to identify the most effective acoustic predictors for VT. MATR, PFTR, and PATR were found to be significant predictors among the variables, with a classification accuracy of 91%. The results indicate that modulation periodicity—reflecting rhythmic regularity in pitch and intensity fluctuations—is a key acoustic feature distinguishing VT from ADLD and MTD. These findings are consistent with the perceptual characteristics of VT and suggest that MSP-based acoustic analysis provides a reliable, objective tool for VT diagnosis. Furthermore, the study indicates that fluctuation-based measures have clinical value in the assessment of vocal tremor.