Improved vocal tract model for the analysis of nasal speech sounds

This paper presents the extended tube model for the vocal and nasal tract, in which the velum is described by means of a three-port-adaptor, which can be reduced to a two-port-adaptor. In this way the transfer function is derived, then its properties are investigated, so that this model can be used for the speech analysis of the nasal and non-nasal sounds and can be simply implemented by the inverse filtering method. Moreover the losses in the vocal and nasal tract are analysed and the shape of the nasal tract is also estimated.