A parametric model of area functions for vowels and consonants has been improved to allow for a more realistic modeling of the vowel [u] and to produce more realistic prototypes of [ae] modeled alternatively as a front or a back vowel. Inversions from formant frequencies to area function parameters are performed in two stages. The first is a codebook lookup and the second is an optimisation procedure. Present experience is limited to vocalic area functions. Our present system provides a rapid conversion of formant frequency data to VT parameters and has provided promising results for short sentences.