Did you know that a ducks quack does not echo, and nobody knows why? I recently received an email with a list of little known facts among which this claim was stated. Immediately the claim seemed impossible and negated everything i had learned until now.

With the threat of my whole belief system at stake i had to get to the bottom of this. How could a sound not echo? It would be like having light that did not shine!

What could there possibly be about the sound a duck makes that would uniquely exempt it from physical laws that apply to all other such sounds? The answer was none. It turns out the quandry was bugging some other people who decided to test a duck inside an echo chamber. The myth was empirically disproven here.

Ducks dont usually hang out near reflective surfaces and in the event that one did and somebody was in ear shot ... there is only one exception i can think of that would imitate the absence of an echo. If a person was standing at the exact distance from the duck and the reflective surface that would shift the phase precisely 180 degrees the echo and the original sound would synchronize and would appear to lack an echo. Occasionally urban myth is created and once a theory like this is presented ... people rarely question it and just put it down to another invention in this amazing world.