Straw Oboes

What's a drinking straw got in common with an oboe? Both can make an almighty racket in the right hands (or mouth).

The straw's flattened triangular tip acts like an oboe's reed and blowing air across it causes the straw to vibrate. This creates a standing wave in the air along the length of the straw which we hear as sound. As you shorten the straw you shorten the wavelength of the standing wave and so increase the pitch of the note.

But an oboe player doesn't chop the end off their oboe to produce a higher note - they change the number of holes covered up with their fingers instead.

This has a similar effect: if you uncover all the holes on an oboe you are effectively creating a shorter tube and so a higher pitched note, but cover up all the holes and you create a long tube and a lower pitched note.

Unfortunately, unlike an oboe, once you've cut your straw down, you can't make it into a long straw again so playing a tune is almost impossible. You could of course cut a series of straws to different lengths and switch between straws to play your favourite song. If you do manage to play a tune then why don't you email us and let us know what it was.

Find out how to perform this and many other tricks with Physics to Go.

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