IN AN excellent description of the vocal apparatus of chickens, Myers (1917) reported that cutting the tracheae of live roosters resulted in higher pitch during crowing. To our knowledge this is the only reported attempt to relate the anatomy of the respiratory tract to the sound produced by the chicken.
MATERIALS AND METHODS
Sounds similar to normal squawks were produced in dead White Leghorn roosters by blowing air through a rubber hose connected into the abdominal air sac by means of a hypodermic needle. The beak, glottis, and trachea were manipulated as described later, and the resulting sounds were recorded on a Wollensak model T 1500 tape recorder. Also recorded were sounds produced by blowing through the syrinx mounted under two different tensions in the chamber described by Gross (1964). These recordings were played back on a Wollensak model 5150 tape recorder into a Sonagram (Kay Electric Co., Pine Brook, . . .