Whistle register and biphonation in a child's voice.

This paper deals with high-pitched vocalizations of a normal healthy child. In the transition region between whistle register and falsetto frequency jumps and coexisting pitches ('biphonation') are observed. The recorded signals are compared to simulations of an asymmetric two-mass model of vocal fold vibrations. As a possible mechanism of the whistle register vortex-induced vibrations are discussed.