Analysis of bright and dark timbre and vocal tract shape in singing expression

Abstract

This study examines bright–dark timbre in classical singing by combining real-time magnetic resonance imaging of vocal tract configurations, acoustic analysis of the singing voice, and acoustic sensitivity values derived from vocal tract area functions. Professional singers produced bright, neutral, and dark in perceptual evaluation. Shape analysis showed a smaller pharyngeal cavity on the laryngeal side in bright than in dark, while oral cavity area and lip-opening showed no systematic change. Acoustic sensitivity functions indicated negative sensitivities of the first and second formants toward the laryngeal side within the pharyngeal cavity, consistent with formant shifts. The third formant exhibited no consistent trend across singers.