Individual Passaggio Identification Based on Laryngeal Surface Vibration Ratios Measured by Laser Doppler Vibrometer

Passaggio is a natural physiological phenomenon during vocal register transitions in singing, with its pitch location varying across individuals. Conventional identification methods rely on auditory judgment or voice type classification, which are inaccurate due to individual differences. In this study, a laser doppler vibrometer (LDV) and an acoustic microphone set were used to synchronously measure laryngeal surface vibration and singing voice，in order to systematically investigate singing passaggio behavior. The data indicate a stable fundamental frequency correspondence between the laryngeal vibration signal and the acoustic signal, which supports the use of amplitude ratios of low-order harmonic peaks in the laryngeal vibration spectrum as relative indicators of structural changes in laryngeal vibration. The result shows that male and female singers exhibit distinct patterns of structural change in laryngeal vibration during passaggio, while consistent patterns are observed within the same sex. For individuals, clear structural transitions in laryngeal vibration are observed at the pitch of passaggio, providing a basis for accurate identification of individual singing passaggio.