Acoustics of Bird Song-Some Unresolved Problems

Abstract

The present state of our understanding of the acoustics of bird song is reviewed from the viewpoint of a physical scientist. It is concluded that the standard model for the production of voiced song, in which the vibrating syringeal membranes act as a pressure-controlled flow valve, is adequately established, in that it is possible to explain most of the features observed in such song with a good measure of quantitative success. The mechanism for production of whistled song is not yet established, but three alternative proposals are put forward in sufficient detail that they can now be subject to anatomical verification and, if not ruled out on such grounds, used as the basis of a quantitative model. The most attractive of these proposals involves excitation of the syringeal membrane by a wave-like disturbance on a jet flowing tangential to it. The resonant properties of the interclavicular air sac may also be involved. Show more