Figure 4.

Comparing the important flow parameters affecting on the sound quality in both the asymmetric and symmetric cases. (a) The fluctuation amplitude of volume flow rate, which represents the strength of the vocal fold vibration. (b) The time-rate of change of the volume flow rate, which is related to the monopole sound strength. (c) The mean value of volume flow rate which is indicative of the flow impedance. (d) The leakage, which is the average of minimum volume flow rate over cycles, reveals the glottal gap size.