Paul's right about the Pro-Ears. IMHO, the electronics are superior. They don't clip sounds, they suppress them, and you don't get that staccato cutting in and out.
I use the Pro-Ears Dimension Pro-Tac DLC "chop-side" model. It's the smallest and lightest electronic earmuff on the market today, and it doesn't interfere with shouldering rifles or shotguns.
You should "double plug" if you're going to be using it indoors. I rarely shoot indoors so it's not an issue for me.
One more thing about the Pro-Ears... you can select sensitivity by moving a jumper to one of three positions. If you want to enhance hearing for stalking while hunting... you got it... just move the jumper. It's like your standard computer jumper; a pair of needle-nose pliers is all you need.
IOW, my Pro-Ears DLC "tactical" model becomes a DSTL "hunting" model just by moving a jumper. Pretty cool.