Vocal Tract Configurations And Formant Pattern Variation In Ruffed Lemurs Vocal Production.

Lemurs, as well as many non-human primates, have large and acoustically diverse vocal repertoires. However, our understanding of the phonatory mechanisms underlying such acoustic variation is very poor and very little attention was dedicated to sources of acoustic variation in the vocal production of lemurs. Looking at ruffed lemurs (Varecia variegata) vocal production, we found that certain calls show the absence of mandible movements, while in others there is a constant articulation during phonation. In this study, we investigated the dynamic variation of several vocal parameters in 5 of the most distinctive vocalizations of the ruffed lemur vocal repertoire. We then compared results with the acoustic response of ruffed lemur vocal tract models.