Figure 2
From: Biomechanics of sound production in high-pitched classical singing
Simulation of hypothetical frequencies for impinging jet sound production in humans, using the model presented in20. The resulting frequencies scale linearly as a function of volumetric airflow V. The figure illustrates the case of V = 150 ml/sec, i. e., a default flow value seen in human singing36. (A) and (B) isoparametric curves for emerging mode-1 frequencies (i.e., lowest possible stable frequency of a whistle) as a function of glottal area (AGL) and impingement length (x). The gray area in (A) depicts the fundamental frequency region of the “whistle” register in female operatic singing37. (C) Strouhal number St (a dimensionless quantity describing the oscillatory flow mechanism). Stable vortex whistles are expected at d/x < St < 1, where d is the jet diameter.
