The effect of glottal opening on the acoustic response of the vocal tract (original) (raw)

In the source-filter model of speech production it is assumed that the acoustic source mechanism is independent of the vocal tract acoustics. In fact, the changing acoustic boundary condition at the glottal end of the vocal tract may be expected to affect the formant frequency and the formant bandwidth, with a corresponding effect on voice quality. In this study, a geometrically simplified physical model of the vocal tract, larynx and sub-glottal tract is used in the presence of an external applied sound field to quantify the changes to the acoustic response of the vocal tract with changing glottal width. The applied sound field is tonal, generated by a loudspeaker, at frequencies ranging from 300 Hz to 2 kHz. The acoustic response of the vocal tract is measured with a pair of pressure transducers, spaced 8 cm apart, and mounted flush with the vocal tract wall. The acoustic transfer function from glottis to lips of the vocal tract is calculated from the measurements using the method...