Theory 38/Strouhal Number/Voice
Voice Is a Strouhal Problem
The claim
Vocal fold oscillation frequency is set by the Strouhal number of the airflow rather than by fold tension alone, so the same tension produces different pitch at different pressures.
01Mechanism
The folds are driven by flow-induced oscillation; the ratio determines when the instability sustains, and therefore the frequency.
02Prediction
Pitch should track Strouhal at equal tension.
03Refutation
Pitch tracking tension alone would remove the flow term.