That would be the Brown Noise.
There was actually a lot of research done in this field in the 1960s. Seems to me it was in the low 20 Hz range that it was thought they could do this.

The theory is that you can generate a sound that is approximately the resonant frequency of the abdominal cavity, causing vibrations to irritate your colon so you got instant diarrhea. An interesting concept, to be sure. Only one little hitch:

No two abdomens are quite the same dimensions. My belly is a different size from yours, which is a different size from that of Tourette's, which is a different size from rachelswipe's, which is a different size from Pooflake's, which is a different size from Prince Harry's, and so on.

Too bad, really- it would be a lot of fun to hack into the speakers at a Spice Girls Reunion concert and make the crowd think that it was the music that gave them the squitters.
( The Resident Loon Not a demographic. Do not measure., Thu 3 Jul 2008, 14:25, Reply)