Not just useful for a gun range; I heard them kick in as I slammed a stubborn door shut. Their 'audio restoration' circuit can be turned up to make it easier to hear things around me than I could without the cans on. Or I can turn them off, and have a very nice, quiet environment. I've currently got them plugged into the laptop, listening to Pandora as I write this.
And they keep road noises to safe level while I wait for the bus, and they keep my ears warm in the cold wind.
Only downside so far...other people looked a tad freaked out seeing me walking or standing on the street while wearing them.