Abstract
Introduction Speech, one of the main functions affected by cleft palate, involves a complex orchestra
of sound deformation by various organs including the larynx, pharynx, epiglottis,
palate, tongue, lip, and other structures complementing them. Although the effects
of palatoplasty are traditionally evaluated subjectively, objective parameters have
seldom been described to compare the pre- and postrepair functions. The study tries
to extract the palatal and pharyngeal muscles while uttering various Hindi syllables
and tries to find the percentage contraction of these structures as an objective assessment.
Materials and Methods Digital Imaging and Communications in Medicine (DICOM) images while uttering each
syllable of the Hindi syllable are obtained by subjecting a healthy volunteer to a
dynamic magnetic resonance imaging (MRI). Using freeform geomagic software, 3D models
of the structure of the pharynx and palate were created, which were then used to create
a finite element model. Different anatomical constraints were applied to the muscles
obtained. The finite element model was tested for convergence and a suitably fine
mesh was used to obtain the results. The percentage of contraction of the palate and
pharynx for uttering different syllables was thus evaluated.
Results The palate and the posterior pharyngeal walls yielded different contractions for
different syllables independent of each other. The highest contraction for the palate
and posterior pharyngeal wall was for the syllable /k/ and the lowest regarding the
palate was for /h/ and /eː/ for the pharyngeal wall.
Conclusion Using computational modeling, quantification of speech in terms of percentage contraction
of the palate and pharynx has been attempted for the Hindi language. Once validated
with a larger population, the database may be used to quantify speech deformities
due to structural pathologies in terms of palatal and pharyngeal contractions and
help us assess the effectiveness of corrective surgeries for them.
Keywords
Devnagri script - computational modeling - speech - syllables - palate - pharyngeal
- contraction
