I have experienced this as well. So many times I would get annoyed at roommates talking incessantly through the night, but sometimes I would realize they weren't. But then who was talking? It only ever happened when the a/c was running. I kind of blocked it out but what you describe is very familiar to me. Auditory pareidolia makes sense to me. It's the most comforting explanation anyway.
I've experienced audio hallucinations from the mentioned potential causes but not like your case. Oscillating fans sometimes tone out a melody loop, while A/C units can whisper out a quick word that sounds name-like. When I was young, I had a neighbor who had a ham radio that would pick up on my little AM/FM radio player's antenna. Nowadays with more digital advancements tapping into the electro-magnetic field, sound can sadly perish to strategic tactics. I would try using a portable fan and see if it has some breaking news to broadcast. All the best.
You're welcome. My wildest hypothesis on the topic is one of science fiction. Consider if there was some long-term frequencies added to LSD, or some kind of other chemical coding, which would use the spinal cord as a remote antenna.
