| "A Duck's Quack Doesn't Echo, and no-one knows the reason why?"
Imagine the duck flying past a cliff side. It is possible to use an electronic effects box to produce the sound you might expect. In this example, the echo path is about 50m, and the echo attenuated by about 6dB. While the echo can clearly be heard when compared to the duck with no reflections, it might be hard to say there was an echo present if you hadn't first heard the anechoic recording. Consequently, a duck's quack does echo, but in many circumstances will be hard to hear. Duck past cliff in WAV format (28k) - Duck past cliff in MP3 format (4k)
So a duck's quack does echo. Which leads to the most interesting question, why did the myth arise? The are a few possible explanations that I can think of:
The quack does echo, but it is usually too quiet to hear. When you want to hear an echo, you usually make a very loud noise to make sure the reflection can be heard. But a duck quacks too quietly, so the reflection is too quiet to hear. Ducks don't quack near reflecting surfaces. You need a large reflecting surface, a mountain or building for the sound to reflect off. Maybe ducks don't hang around reflecting surfaces.
It is hard to hear the echo of a sound which fades in and fades out.
Where is Daisy now?
Daisy was kindly lent to us by Stockley Farm in Cheshire. This is a working farm open to public, so you can go and see Daisy in person if you wish. We think Daisy now deserves retirement, and so we are going to investigate other acoustic myths.
Do you know of any worth investigating?
Go to our feedback page and send us your suggestions