Here are some posts I made about it awhile back:
http://www.titantalk.com/forums/659436-post7.html
http://www.titantalk.com/forums/660336-post14.html
Here is the entire thread:
Who's Got A Bazooka Tube?
The Bazooka's have a yellow loop that makes it auto-turn on/off..when it detects sound, it will turn on; when no sound detected, it turns off.