communication through auditory signals usually produced by a vibrating organ, such as the larynx in the throats of some mammals or the two syringes located in the bronchial branches in birds. Vibrations produced by these organs are altered by changing configurations of the tongue and lips and the shape of the oral and nasal cavities. Other sound-producing mechanisms in nonhuman animals include stridulation, the rubbing together of body parts, as in crickets. See also animal vocalization.