This paper presents predictions of the consequences of tongue surgery on
speech production. For this purpose, a 3D finite element model of the tongue is
used that represents this articulator as a deformable structure in which tongue
muscles anatomy is realistically described. Two examples of tongue surgery,
which are common in the treatment of cancers of the oral cavity, are modelled,
namely a hemiglossectomy and a large resection of the mouth floor. In both
cases, three kinds of possible reconstruction are simulated, assuming flaps
with different stiffness. Predictions are computed for the cardinal vowels /i,
a, u/ in the absence of any compensatory strategy, i.e. with the same motor
commands as the one associated with the production of these vowels in
non-pathological conditions. The estimated vocal tract area functions and the
corresponding formants are compared to the ones obtained under normal
condition