Presumed Lost,
I haven't had any tests done on decibels, but I have field tested it and I think it compares well with most plastic whistles. It won't keep up with a Storm whistle, but once again I had to free up some room. As far as how much breath it takes to blow it, I can't notice any extra effort needed to make it work. It is basically the same size as a Classic, but it's considerably thicker. I've carried a Classic for years, but now I'm sold on the Classic Whistle.
Hope this helps, George