Noisy bubbles to guide the fishes
Tuesday, August 11, 2009 at 18:45
I was reading this month's edition of Wired magazine when I came across this article. To keep a swarm of Asian carp from invading the Illinois River and disturbing the native fish, ecologist Greg Sass is experimenting with 'noisy bubbles'.
By using air bubbles combined with high, chirping sounds, the carp invasion is stopped. Carp can hear sounds up to 2kHz, frequencies the native fish can't hear. A curtain of bubbles and noise creates a loud 'wall of sound'. Sound in a bubble-water mixture can become extremely loud.
I never heard of such a 'bio acoustic fish fence', and one might question if we should interfere with nature at this level, but the idea of using the sensitivity of a certain species' hearing combined with the known properties of sound is at least thought provoking.
Sound is used in so many clever ways in this world, in places we don't know about. It makes me wonder what other purposes sound can have, in a completely functional, un-aesthetic manner. It's fascinating to discover what we can do with sound, and how it can help us in this world.
Do you know of any interesting, strange, unconventional ways of using sound? I'd be happy to hear.
Picture by The Artifex
Reader Comments (6)
you've heard of the 'mosquito' that emits an irritating high frequency that only teenagers can hear so it keeps them from hanging around outside shopping centres etc.?!
Or that Fanta ad campaign where depending on your age group, you download a ring tone of a higher frequency than what older people then you can hear. Brilliant!
I've used a (very short!) high frequency tone to silence the continously barking dog in the garden of the neighbours.
I really felt sorry for the dog, but the owners didn't educate it and locked it up. Letting the dog bark for days on end was unacceptable for me (and other neighbours I imagine). All is fine now, the dog only barks occasionally, which is fine by me.
And remember THE BROWN NOTE? :)
http://en.wikipedia.org/wiki/Brown_note
Forget the brown note, what about the tampon-shaped high frequency body immobilizer thingy in Iron Man? Kinda resembles the tampon-shaped memory correction thingy in Men in Black..
@Michael: Yes, I heard about that anti-teen 'mosquito'. Actually I heard one myself one time, very annoying! I guess it would only work at a home for the elderly, as there are many people who can still hear those frequencies!
@Sndr: A good idea! Did you just take a random high frequency or a specific one which annoys dogs?
@Josephine: I haven't seen Iron Man yet. But I was actually talking ehhm... non-fiction?!