I think the hotels that allow dogs also have outdoor play areas and commons areas for all the dogs to play in. I'm not sure how well your dogs would get along with the others though or if they allow you to leave them unsupervised in those areas. Honestly, if its a dog friendly hotel, I'm sure everyone knows what they are getting into before checking in to the place. It's kind of common sense that you're going to hear other dogs barking regularly.
I've seen some that have private dog rooms for each dog, they have a little bed and couch for them - kind of like an oversized glammed up kennel. It would make sense, since I'm sure the hotel also wants to make money off you having dinner in their lounge/bar/restaurant as well.
