I think these are just really common hallucinations that can be caused by a lot of things. I've had them when nearing heat stroke, but also from various substances. I write it off as brain doing what brain does best; over active pattern matching due to stress or the like. Hearing music in white noise, "whispers in the walls" etc. Very different from actually hearing personified voices.
Yep. I've had this happen to me since I was a kid, and it's ramped up slightly over the past few years. Background noise especially at night, will seem to form music, or the sound of dialogue of a television through a wall.
Usually just sitting up and accurately identifying the source of the sound (ceiling fan, radiators, passing train, cat water bowl) makes it go away.
My brain is very bad at identifying what people are saying with background noise, but at least I get free night music.
I only get this with very faint white noise in very quiet environments. Humans can actually sense things under the noise floor, so the line between hallucination and truth is blurry.
