5th International Conference on Spoken Language Processing
For nasal vowels, a gesture as simple as the lowering of the velum produces complex acoustic spectra. However, we still find a relative simplicity in the perceptual space; nasality is perceived easily. In this preliminary study, we use statistic method to recover the gesture of the velum. In order to reduce the extreme variability of nasal vowels, we introduced a simulation based on Maeda's model instead of using a natural speech signal. In previous studies, nasality is supposed to increase either with size of the nasal area or with the area ratio between nasal and oral tracts at the extremity of the velum. In this work, both types of data are considered and analyzed with linear and non-linear tools. Finally, statistic inference is described and results are given for various areas of the nasal tract entrance and for various area ratios. The results show that velar port area is correctly estimated for small values while area ratio is a better parameter when velar port area increases.
Bibliographic reference. Rossato, Solange / Feng, Gang / Laboissiere, Rafael (1998): "Recovering gestures from speech signals: a preliminary study for nasal vowels", In ICSLP-1998, paper 0540.