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Abstract:
A number of models begin to appear in the literature, linking
perception and action in a quantitative computational framework.
However, in this framework, models of tactile sensors are badly
lacking, though their role is generally considered as important
in speech control. The purpose of this paper is to present a
preliminary model of palatal tactile perception. First, we
propose a review of a number of behavioural and
neurophysiological data about orosensorial inputs and their
potential role in speech production, particularly in perturbed
conditions. Then we introduce the principles of our model, and a
precise description allowing its reimplementation by anybody
interested. Our departure point is a series of palatographic data
on vowels and plosives in vocalic context published in the
literature (Recasens 1991; Recasens et al., 1993), associated to
vowel and plosive articulatory prototypes defined on an
articulatory model (Maeda, 1990; Boë et al., 1995). From
these data ! we derived a model enabling to predict the main
characteristics of palatal contact from the articulatory
commands. We show that the model provides a good approximation of
palatographic data. It allows to predict both prototypical
configurations and a large set of variations around these
configurations due to coarticulation and tongue-jaw
compensations. Then, to demonstrate the interest of this model,
we realised a large articulatory-acoustic-"palatographic"
dictionary (with more than 1,000,000 sets) and we selected all
configurations providing a configuration of palatal contacts
around the one for our prototype of [i]. We show that the
configurations are all associated with the same values of these
"acoustically significant area-function information" mentioned by
Gay et al. (1981), that is the location and area at the point of
maximum constriction: typically, with a small front constriction.
Hence this model of tactile sensor could provide a very important
set of orosensory in! formation useful for speech acquisition and
speech control in normal and perturbed conditions.
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