Is it true a duck's quack won't echo?
Recently I read the useless fact that the quack of a duck will not echo. (1) Is this true? (I currently do not have access to either a duck or a canyon, or I would find out myself.) (2) Why not? (Assuming it is true.) (3) Are there other noises that will not echo? (4) Again, why not?
This is another example of faxlore — myths and factoids kept in circulation by people who evidently will believe anything. Next time I organize a poker game, I know whom I want to invite.
Personally, I recognized this claim immediately for what it was — quackery. Preliminary inquiries confirmed this. Sure, there's such a thing as destructive interference, in which colliding waveforms cancel each other out. But how this would cause 100 percent attenuation of an echo 100 percent of the time in uncontrolled conditions was beyond even me.
But never mind my opinion. What we need here is science. Knowing the only way to settle the question for good was an experiment, I assigned Jane to assemble the apparatus and conduct a test. Here is her report:
"I spoke with several friends about the duck's quack question, even called the Michigan State University animal science department. No one could confirm or deny the claim, and no one at MSU seemed eager to stage a formal experiment, the wimps. I mentioned my dilemma to a visiting friend, and he said his wife, Shareen, had an in with the director of Mott Hashbarger Children's Farm and School in Flint. She had, on occasion, borrowed farm animals for events, and she was willing to get a duck and bring it down. After a quick phone call to the farm director, who gave his blessing, she obtained a duck and put it in a pet carrier.
"But where to find a good echo? I live in mid-Michigan, after all. I called Glenn Brown, a sound engineer who has done work across the country. As luck would have it, Glenn remembered one place where, as a kid, he would go to produce great echoes. It's at the back of East Lansing High School — a sort of courtyard between two classroom wings, about 30 feet wide and 170 feet long. The hard surface of the buildings and perhaps a low hill opposite are highly conducive to reflecting sound.
"So, with friends, duck, and camera in tow, we drove to ELHS. In the courtyard without the duck we easily produced some impressive echoes. Next we got the bird and sat down in the middle of the courtyard. We thought he would produce a big quack and the experiment would be over. No such luck. He just wouldn't quack. Probably he was nervous. Who wouldn't be? He was a sitting duck.
"The three of us certainly quacked, though, such that we thought we might want to change the name of the experiment from 'does a duck's quack echo' to 'how to make three humans quack like a duck.' We tried to be inconspicuous, since school was in session and students could see us. However, a duck and three quacking humans is not the sort of scene that fades readily into the woodwork. The duck quacked in the cage, which was useless for our purposes, but when we took him out he was mute.
"Finally Shareen had an inspiration. She held the duck by his body so that he could flap his wings, and ran up and down the length of the courtyard hoping to replicate the experience of flying. So much for being discreet. Incredibly enough, this wacky stratagem worked. The duck loved it and quacked like crazy for a minute. Yes, the quacks echoed. This was heard by the three of us and by an unidentified East Lansing High School teacher who came out to make sure we weren't engaging in duck torture. I was able to record the event but didn't get a good sound recording of the echo itself. But I do have a dandy clip of Shareen running up and down with the duck. I call it my 'duck tape.'
"I wanted to reward my friends somehow, and offered to buy them lunch. They asked for roast duck. They're such comedians. They settled for soup and quackers."
That Jane. What can I tell you? She quacks me up.
Our results confirmed
UK scientists, following up on our pioneering research, have now corroborated our finding that a duck's quack does in fact echo. However, acoustics expert Trevor Cox, who recorded quacking ducks under controlled conditions at Salford University's Acoustics Research Centre, says there may be an element of truth in belief to the contrary. According to a BBC report, "[Cox] says the way a duck quacks, with a long 'aaaacckkk' on the end of the call, tends to mask any echoes that are produced." Could be, Trev. We don't claim to have written the final word. We're just glad to have done our bit to advance the frontiers of knowledge.