Transformations of speech spectra to a two-dimensional continuous-valued phonetic feature space for vowel training

A vowel articulation training aid for the deaf has been developed. This is an improved digital system processor (DSP) version of the analog filter-bank system presented by S.A. Zahorian and S. Vankat (1990). The real-time signal processing strategy and the mapping of the continuous feature space to a two-dimensional display space are described. A combined linear/nonlinear transformation, in the form of an artificial neural network, is used to convert cepstral coefficients to a 2-D space suitable for computer displays. A multistage artificial neural network training algorithm has been developed that yields better performance and reduced training time relative to conventional training techniques