Finite element modelling of vocal tract changes after voice therapy

The generated acoustic pressure of the response was computed in front of the vocal tract for both FE models. The formants F1 – F3 correspond to classical vibration modes also solvable by 1D vocal tract model. However, for higher formants, there occur more complicated transversal modes, which require 3D modelling. Comparison of the pressure oscillation inside and outside, the vocal tract showed that formants differ in their efficiency, F4 (at about 3,5 kHz, i.e. at the speaker’s or singer’s formant region) begin the most effective. The higher formants created a clear formant cluster around 4 kHz after the vocal exercise with the tube. Since the human ear is most sensitive to frequencies between 2 and 4 kHz concentration of sound energy in this frequency region (F4-F5) is effective for communication.