What Jim Watson said. Electronic muffs are superb for a busy range situation, enabling you to hear commands and commentary whilst remaining protected. Also, using plugs under them, and turning the volume up, allows you to hear range commands while still benefiting from the double protection.
Another useful feature is that if your home is invaded, or you're in a tactical situation, they can amplify your hearing to where you can get the drop on your opponent by the sound cues he makes. Of course, you need genuine stereophonic reception for this - the cheaper muffs give you the same sound in each ear, which makes it difficult to determine where the sound is coming from.