[Image:Syrinx.jpg|right|framed|
Schematic drawing of an avian syrinx1: last free cartilaginous
tracheal ring,
2: tympanum,
3: first group of syringeal rings,
4: pessulus,
5: membrana tympaniformis lateralis,
6: membrana tympaniformis medialis,
7: second group of syringeal rings,
8: main bronchus,
9: bronchial cartilage]]
Syrinx (
Greek σύριγξ for
pan pipes) is the name for the vocal organ of
birds. Located at the base of a bird's
trachea, it produces sounds without the
vocal cords of mammals. The sound is produced by
vibrations of some or all of the
membrana tympaniformis (the walls of the syrinx) and the
pessulus caused by air flowing through the syrinx. This sets up a self-oscillating system which modulates the airflow creating the sound. The muscles modulate the sound shape by changing the tension of the membranes and the bronchial openings. The syrinx enables some species of birds (such as
parrots,
crows, and
mynas) to mimic human speech. Unlike the
larynx of mammals, the syrinx is located where the trachea forks into the lungs. Thus,
lateralization of bird song is possible and some songbirds can produce more than one sound at a time. Some species of birds, such as New World
vultures, lack a syrinx and communicate through throaty hisses.