Kokua Line: Can service dog be left alone at hotel?

Question: I know some hotel chains are pet-friendly and I avoid them. I check before I make a reservation and choose one that does not welcome pets. I know they must accept service dogs, but that’s different, required by law. If I stay in a hotel that says it does not accept pets and yet I hear a dog barking in the next room for a prolonged period (apparently alone), what can I do? When this happened I assumed it was a service dog and suffered through the noise.