AEROACOUSTICS OF THE VOCAL ORGAN OF BIRDS

A model is presented of aeroacoustical processes occurring in the avian syrinx during vocalization based on current anatomical and physiological knowledge. The physical circumstances governing the triggering of oscillations in the external tympaniform membranes are analysed. A theory of membrane excitation based on non-linear elasticity is described. Anatomical and physical factors controlling the level of sound power radiated are examined and the possibility is considered that elevated airflow rates during vocalization may increase power output by a process of convective amplification similar to that which has been described in certain engineering contexts. © 1979.