An Extension of Flanagan's Model of Vocal‐Cord Oscillations

An extension of Flanagan's model for vocal‐cord oscillations has been used to excite a transmission‐line analog of the vocal tract and thereby synthesize voiced and unvoiced stops. Postulation of a two‐spring vibrating system allows the lateral compression of the vibrating vocal‐cord mass to be a nonlinear function of the force exerted by the air on the cords. When the supraglottal pressure is low, e.g., for an unconstricted vocal tract, the vibrating system is essentially linear and reduces to that proposed by Flanagan. When the tract is constricted, e.g., for voiced stops, the nonlinearities introduced serve to limit expansion of the glottal area in spite of the higher air pressure on the vocal cords. Unvoiced stops are modeled by an active separation of the vocal cords which switches the oscillator from an oscillatory stationary mode. Examples of simulations of intervocalic voiced and unvoiced stops are given.