Beak and Singing

Program Description

The beak of a bird is part of its airway. By altering the opening of the beak, a bird alters the shape of the airway and modifies the sounds it sings.

You can get a sense of the importance of the shape of the airway by noticing how different a trumpeted length of PVC pipe sounds if a flared bell is attached to its end: it's a sweeter, more musical, somewhat higher sound.

Large billed birds with long necks may get some of the effect of a flared bell by opening their beaks. But for most smaller birds, this effect is small. But there are lots of ways a bird can shape the airway to modify the sound made in the syrinx (voicebox). These don't rely on the beak being large enough to produce the effect of a flared bell.

As we'll see in the next program, the way we humans shape our airways is absolutely crucial to our communication: among other effects, airway shaping is what lets us differentiate vowel sounds.

Program & Recording Notes

Chris Tenney recorded the house finch and the northern mockingbird in Salinas.

I found this recordings of the sandhill crane on the International Cranes Foundation website.

The mourning dove recording is from the CD collection Bird Songs of California produced by the Cornell Laboratory of Ornithology.

The tones of the lengths of PVC pipe (with and without a flaring bell) are from the brass acoustics page of Joe Wolfe's wonderful music acoustics website at The University of New South Wales.