How Birds Produce Sound

BirdNote^®

How Birds Produce Sound

Written by Chris Peterson

This is BirdNote!
[Call of the Brandt’s Cormorant; Song of the Northern Cardinal; Song of the Song Sparrow]
You just heard the grunt of a cormorant, the whistle of a cardinal, and the song of a Song Sparrow. Nearly all birds produce sound through an organ unique to birds, the syrinx. [Song of cardinal]
The syrinx is a set of muscles and membranes located where the two branches of the bronchial tubes converge to become the trachea. An adjacent air-sac helps build pressure in the syrinx. In many songbirds, this whole song-producing apparatus is not much bigger than a raindrop. The syrinx is extremely efficient at creating sound, using nearly all of the air that passes through it. [By contrast, we humans create sound using only two percent of the air we exhale through our larynx.]
Let’s listen again to the limited vocal range of the cormorant, whose syrinx is controlled by only one set of muscles [Call of the cormorant]. The cardinal, a familiar bird of central and eastern states, creates its pure whistle by producing sound in its left and right bronchial tubes simultaneously [Song of cardinal] The Song Sparrow, like many other songbirds, has five to seven pairs of muscles that govern the syrinx. It puts forth a cascade of trills and notes, as if singing a duet with itself [song of the Song Sparrow].
You can hear any episode of BirdNote again, even sign up for the podcast, when you come to our website, BirdNote.org. I’m Michael Stein.
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Bird sounds provided by the Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Brandt’s Cormorant recorded by G.F. Budney; Northern Cardinal recorded by G.A. Keller; Song Sparrow recorded by G.A. Keller.
Producer: John Kessler
Executive Producer: Chris Peterson
© 2014 Tune In to Nature.org     April 2014     Narrator:  Michael Stein

ID# orig: 041105soundKPLU       sound-01b