I tried that with foams and regular muffs and it was very quiet. Too quiet (hard to hear) while on a range with commands or if you need to hear stuff behind you. I then switched to electronic muffs and foams which seemed to work better in those applications. YMMV of course.

As far as the OP's question, I use an electronic pair of Howard Leight ear muffs that I picked up from Cabelas when on the range and giving commands. The electronic muffs block the loud stuff and you can still hear people talking when you need to.

If your in the field a good set of electronic muffs or plugs. For shooting practice just regular muff and indoors I'd double with muffs/plugs. The only time at a public range when you need to double is when someone decides to bring a rifle that is doesn't belong in a busy range so you have to double your protection. If your firearm is loud enough that it requires double hearing protection shoot it at your own property or when the range is empty.

I got a pair of the Howard Leight hearing enhancers so I could hear turkeys gobble, etc. But the things also work well to reduce sounds even while on amplification.

While shooting: muffs and foam plugs together. During cease fire times I remove the muffs and leave in the plugs. The public range I use has a very loud PA system - it is loud in order to be heard over gunfire. However during the cease fire period the PA is almost painfully loud. So during cease fire I remove the muffs to hear any range officer commands but leave in the plugs to protect my ears from the PA system.

And yea those muzzle breaks are freakin' loud!

I'm curious if anyone has tried the electronic Radians? I can't stand ear muffs I'm back to using foam ear plugs.