Abstract (eng)
The study of communication systems is a central issue in the understanding of animal behavior, ecology and evolution. In mammals in particular, vocal communication has drawn considerable attention, starting with purely descriptive approaches, until more recently when the source-filter theory was applied from human speech to mammal acoustic signals. This framework has allowed fundamental progress regarding the interpretation and investigation of the function of vocalizations. Nonetheless, the mechanisms of sound production, an entire branch of vocal communication, have largely been neglected in terms of their biological relevance (the physics being relatively well explicated by the myoelastic-aerodynamic (MEAD) theory).
Relying on the source-filter theory, in this dissertation I highlight how current methodologies and knowledge about mammalian vocal communication are implemented in the field, either while initiating the study of a new species’ vocal repertoire or while decoding in-depth some characteristics of an already well-known model species. I then delve into the connection between sound production and vocal output, investigating how anatomical constraints at the level of the sound source can shape a species vocal communication system. More specifically, I study the relationships between physical-anatomical traits of the signaler and their acoustic correlates. Finally, I empirically examine these relationships by means of excised larynx experiments, which provide a unique insight on sound generation.
The studies collected in this thesis provide a multi-faceted overview of the connections that exist between the various components of mammal vocal communication. They establish the foundation for future research intended to explore in parallel the functions and the production mechanisms of animal acoustic signals, including those particular cases where evolutionary pressures have led to specialization of the vocal apparatus and associated vocal displays.