My friend's old job had that exact problem, just one loud room. They finally added a few quiet spots like @jesse_carr23 said and it saved her sanity. She said the mix actually helped people talk more, not less.
When some praised the collaboration, they had a point. The real issue is forcing everyone into one loud room all day. Add some quiet rooms and it becomes a usable setup.
Adding quiet rooms defeats the purpose of an open office. The noise forces quick talks and shared fixes that email can't match. You lose that spark when everyone hides in their own silent box.