A Duck's Quack Doesn't Echo
“A duck’s quack doesn’t echo and nobody knows why,” is an oft-quoted scientific myth.
You won’t find this claim in any reputable scientific papers because of course a duck’s quack does echo, as does every other sound as far as we know. But why is this myth so popular?
A number of reasons have been put forward about the origins of the myth. Ducks tend to quack quietly so perhaps the echo is just too quiet to hear. Ducks also tend to live in open spaces away from large reflecting surfaces such as buildings or mountains for the sound to bounce off and produce an echo.
In 2003 researchers from Salford University’s Acoustics Research Centre decided to bust this myth once and for all.
The team, led by Professor Trevor Cox, borrowed a duck called Daisy and first of all placed her in an anechoic chamber which deadens echoes and then in a reverberation chamber which has cathedral like acoustics where the sound echoes for a long time.
They then recorded the resultant quacks and analysed the sounds.
What the researchers found was that although in the reverberation chamber the duck’s quack was hard to hear when compared to the sound in the anechoic chamber it was quite clear that the quack did echo.
However, a duck’s quack is generally quiet and has a long fading ‘aaaack’ sound at the end which can mask any echoes that are produced.
Professor Cox said, “What all this shows is that the duck’s quack fades away; it sounds like it quacks for a long time.
“Because the duck’s quack is rather quiet anyway and the echo comes on the back of a fading sound field, it is as if the echo is being masked. You just don’t hear the echo very well and that’s probably how the myth arose.”
So although a duck’s quack certainly does echo there does seem to be a scientific explanation for how this myth came about. Although this experiment was just a bit of fun for the research team their work is important in the construction of buildings such as concert halls or cinemas and the design of cars.
And what of Daisy? The duck, who was borrowed from a farm in Cheshire, was unfortunately subsequently eaten by a fox. However, her daughter, unlike her echo, lives on.