a ducks quack does not echo?

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.

You should watch "The Mythbusters" on The Discovery Channel. They studied this myth, but I don't remember exactly what was the result...I belive they prooved that the quack echoes

I read it does not echo and from what I can tell our ducks don't echo. The boys are very quiet almost chirping like but the girls are very loud and quack all day long. You can definitely tell the girls because they are bold and loud and the boys quack out there orders but are very soft and gentle.

When something makes a noise, say a gunshot in a canyon, the observer hears the noise echo around. This is because the sound waves take different length paths on their way to the observer. So you hear the bang and then you hear it again when the sound has reflected off a big rock wall and come back at you. Ducks often live in marsh land or on lakes and I'll stick my neck out to suggest this is more common than finding them in mountains or canyons. So if the duck is in a large open space and it quacks you don't hear an echo because the sound that's travelling away from you has nothing to bounce it back in your direction. I'm suggesting that people hear the echo of a duck's quack less often than they might hear echoes of other noises.

I didn't know that but I imagine it would be true because a duck doesn't project its quack, it stays in the throat. Therefore, it would not bounce back, I guess.