Some will connect to walkie talkies and Peltor makes a set that are walkie talkies. I actually have a set of the walkie talkie versions that I use when operating a Bobcat or on a tractor.
The other option is to go with the ear buds and let them hang loose inside the muffs with the volume turned up. I have done this as well. The muffs provide enough silence to hear the little ear buds just fine, but you don't have to have the sensation of the buds in your ears (which I don't like).
There may be other brands available that do the same thing, but I am not familiar with them...
http://www.envirosafetyproducts.com/...-Headsets.html