The Siren Board

Here's is one of those oddball model 5's sounding for a statewide tornado drill in South Dakota. Skip to about 3:43 in the video to hear the siren and watch the housing wobble. Not my video by the way.

http://www.youtube.com/watch?v=8UqPKo45Ug8

That's not a Model 5, that's a Darley Champion. The YouTube poster said so in the comments. It's sound reminds me of an STH-10.