'faking it - surfer'
quack

i know at least krischelle will appreciate this 'cause we had a conversation about it, but i was just watching mythbusters and they were busting the myth that a duck's quack DOES NOT echo. they hired an 'acoustician', a scientist from meyer sound (who makes some of the best speakers in the world...top of the line for high-volume live concerts...god i wish i could work for them) to both listen and to plot the duck's quack and possible echo(s).

well, they found some interesting things. as a base line they took a recording of the duck's quack in an acoustically baffled room (i.e. completely void of echos)...like a sound booth in music recording. when they took the plot of it (the waveform) the dude found something interesting...the duck's quack basically resembles an exponentially decaying signal. to try and help you visulaize, a gunshot or a clap would be a spike....a gunshot or clap in an empty warehouse (i.e. w/ echos) would be a set of exponentially decaying spikes. identicaly in frequency spectrum, but each one smaller in magnitude until it is ultimately gone.

so what this means is that a duck's quack sounds like it's own echo. if you think of a duck's quack, it sounds like a rapid succession of clicks (for lack of a better word)....similar to if you pursed your lips and blew. it's not really a sound....it's a percussive sound repeated over and over. SO, what that means is that when the quack echos (which it does indeed echo, as i'll explain), it sounds exactly like the original quack. physically, it's just a bunch of those little clicks adding together. mathematically, if you add an exponentially decaying series (the original signal) to another exponentially decaying series (the echos of each individual click), you get an exponentially decaying signal that might have a slightly longer duration and a different rate of decay (slower)....but apparently small enough that it's not discernable by the human ear.

hmm...that was kind of long winded. hope it made sense. i really love this sound stuff :)


echo