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Experiments

The technique of electropalatography (EPG) [35,36] is well established in many speech science laboratories as a relatively non-invasive, conceptually simple and easy-to-use tool for the investigation of lingual activity in both normal and pathological speech. It is possible to obtain qualitative and quantitative data about patterns of lingual contacts with the hard palate during continuous speech. Typically, the subject wears an artificial palate moulded to fit the upper palate with a number of electrodes mounted on the surface to detect lingual contact (62 in the EPG system of [35]). The EPG signal is sampled at 100-200 Hz.

Data reduction of EPG data is possible because the EPG sequence presents redundancy due to physical constraints of the tongue-palate system. This redundancy is both spatial and temporal. Currently we are only investigating spatial redundancy.

We have experimented with a subset of the multilingual EUR-ACCOR database (ESPRIT II Basic Research Actions 3279 and 7098), which was designed for the cross-language study of coarticulation. EPG frames corresponding to the English language were selected and divided into training and test sets. The various dimension reduction algorithms were evaluated on this data.

The results are presented and discussed in detail in a paper contained in the appendix to this report. In summary:


next up previous contents
Next: Non Linear Discriminant Analysis Up: Algorithms for Dimension Reduction Previous: Latent variable models
Christophe Ris
1998-11-10