Hi Yoyoma
I suffered auditory hallucinations due to medications, they were varied, and quite weird. Sometimes it would be like a small grab of a conversation suddenly loud in my ear and then gone again, sometimes it would be the same few lines of a song, over and over again, sometimes it would be parts of a dream that would come back to me the next day or even later, that I had to think really hard about, cos it seemed to be a memory of a discussion, rather than a dream. I never had instructions or anything, but sometimes it would be hard not to swear I heard something.
So I guess in answer to your question, from my experience, it could be both. If you are worried about it please speak to your doctor.
Cheers
Deb