Pole-zero modeling of vocal tract for fricative sounds

This paper presents a pole-zero model based on a multi-tube acoustic model for fricative sounds. This model consists of the front and back cavity formed by the oral tract and pharynx, in which the excitation source is located at the point of constriction. The transfer function of this model including poles and zeros is derived and its properties are investigated. Small losses such as viscous friction which is an important for the fricative sound in the vocal tract are considered and the results show, if the vocal tract is lossless, the numerator part of the pole-zero model is symmetric. The transfer function with small losses overcomes the limitation of the symmetry. This method is applied by employing the inverse filtering and an adaptive algorithm to analyse fricative sounds