I would expect ear protection (to avoid damage caused by extreme pressure changes) and volume reduction to be quite different. http://www.wisegeek.com/what-are

I would expect ear protection (to avoid damage caused by extreme pressure changes) and volume reduction to be quite different. http://www.wisegeek.com/what-are-safety-ear-plugs.htm http://www.wisegeek.com/what-are-safety-ear-plugs.htm