Have you talked to your psychiatrist a lot about this? If so, what did she/he say?

I generally only have hallucinations when full blown manic (and usually in the hospital). I have had hallucinations when severely depressed, but not that often, and usually when I was in the hospital. However, I did have musical hallucinations at one point. At the time, I was not significantly manic or depressed. In response, my psychiatrist added Tegretol XR (an anticonvulsant moodstabilizer). I had to start that medication at a low dose and work my way up to a therapeutic level. Actually, my psychiatrist kept raising it until my musical hallucinations went away (but still in a therapeutic level range). Once I reached 1400 mg the musical hallucinations disappeared completely. I have never had them since. Tegretol XR has been my primary moodstabilizer for more than 7 years, accompanied with an antipsychotic.

There was another time that I thought I was having hallucinations. They were more like time and space distortions for the most part, but occasionally I would see and hear things that were so incredibly unlikely that they were clearly hallucinations. My psychiatrist thought that was seizure activity, but it is likely that it wasn't. Another theory was that these experiences were dissociative hallucinations. I can't be 100% sure if that was the case, but once I began to master grounding techniques, these occurrences went away.

Do you only have these auditory hallucinations (when not severely manic or depressed) when just falling asleep? If they do seem very sleep-oriented maybe that's simply the issues. I don't understand such things well, but my speculation on this is only based on the little I learned in psychology classes. Please do discuss your experiences with your psychiatrist. They are the most qualified to get to the bottom of them.