Optical fiber is pretty much mandatory for what you are asking for. Cobranet requires a standards compliant ethernetwork. You can push analog audio over twisted pair cable, the phone company has been doing it since before I was born. I had made the assumption that the application was a single performance venue, where keeping your audio syncronized is critical. For your application, with probably lots of different venues, slight delays of audio arrival are likely not going to be an issue. Is this an amusement park? then you can share the data network with other users, as sporadic delay doesn't matter. If this is a single very large venue, like a race track, then time synchronization is very important for audio intelligibility, which leads you back to a dedicated network.
--Dale