  The velopharyngeal (VP) valve regulates the opening between the nasal and
oral cavities. This valve opens and closes through a coordinated motion of the
velum and pharyngeal walls. Nasalance is an objective measure derived from the
oral and nasal acoustic signals that correlate with nasality. In this work, we
evaluate the degree to which the nasalance measure reflects fine-grained
patterns of VP movement by comparison with simultaneously collected direct
measures of VP opening using high-speed nasopharyngoscopy (HSN). We show that
nasalance is significantly correlated with the HSN signal, and that both match
expected patterns of nasality. We then train a temporal convolution-based
speech inversion system in a speaker-independent fashion to estimate VP
movement for nasality, using nasalance as the ground truth. In further
experiments, we also show the importance of incorporating source features (from
glottal activity) to improve nasality prediction.
