Abstract

For over a century, speech science has assumed that the vocal tract functions as an acoustic resonator, with formants arising from standing waves in the air column. This paper challenges this assumption by demonstrating that pressure fluctuations within the vocal tract during phonation are not acoustic waves but aerodynamic pressure fields (pseudo-sound) that propagate at flow velocities and remain confined to tissue boundary layers. We introduce the Distributed Tissue Vibration (DTV) framework, which relocates resonance from air to tissue. In this view, formants are not acoustic cavity modes but mechanical resonance frequencies of distributed tissues driven by aerodynamic forcing through flow-structure interaction. The transformation into radiating acoustic waves occurs primarily at the vocal tract exit. This framework accounts for phenomena that resist acoustic interpretation, including the whistle register, electrolarynx speech, and voice changes from alterations in tissue properties independent of geometry. Clinical observations, contact microphone recordings, and experiments using a vibration transducer support these tissue-mechanical interpretations. By shifting focus from isolated vocal fold geometry to distributed tissue mechanics across the vocal tract, the DTV model offers a holistic basis for therapy and surgery. It articulates empirical predictions and experimental tests, marking a proposed paradigm shift in voice production theory.

Citation: Kılıç MA. From acoustic resonance to flow-induced distributed tissue vibration: An aero-elasto-dynamic theoretical framework for voice and speech production. Praxis Otorhinolaryngol 2026;14(3):i-xvii. https://doi.org/10.5606/kbbu.2026.25.