Simulations of fallow deer groans from CT scanned vocal tracts
Résumé
Males of several species of deer have a descended and mobile larynx, resulting in an unusually long vocal tract, which can be further extended by lowering the larynx during call production. We CT-scanned the head and neck region of two adult male fallow deer specimens with artificially extended vocal tracts and measured the cross-sectional areas of the supralaryngeal vocal tract along the oral and nasal tracts. The CT data were then used to predict the resonances (formants) and the transfer function between the glottis and a point outside. Modelling the source signal as a succession of impulses, we synthesized groans using the calculated transfer functions. We discuss the effects of vocal tract length and potential nasalization.