It echoes.
Not that I would ever doubt Cecil, but I just want to confirm that I have indeed heard the echo of a duck’s quack.
At this time of year, the mallards on the river often come downtown to spend the night under parking lot trees. This morning when I got to work, there was a female mallard quacking it up in a courtyard between two of the buildings. Perfect acoustics!
I wonder what is the origin of the quacks<>echo legend, anyway?
http://www.straightdope.com/classics/a5_071.html
Your brain-in-a-jar,
Myron
Imbibo, ergo sum.