What vibrates in a whistle?

In a whistle, the part that vibrates is called the fipple. The fipple is a thin piece of metal or plastic that is positioned in the airstream of the whistle. When air is blown across the fipple, it creates a jet of air that vibrates against the sharp edge of the fipple. This vibration produces the high-pitched sound of the whistle.

The pitch of the whistle is determined by the size and shape of the fipple. A larger fipple will produce a lower pitch, while a smaller fipple will produce a higher pitch. The shape of the fipple also affects the tone of the whistle. A rounded fipple will produce a softer tone, while a pointed fipple will produce a sharper tone.

Whistles are used in a variety of applications, including music, signaling, and sports. They are also used in some scientific instruments, such as the wind tunnel.