I had a very similar experience during a dysphoric hypomania. I also heard an unidentifiable voice, it was saying I was stupid. I heard it with my ears. One of the weirdest experiences I've had.

I just remember sitting there quietly knowing I had just had a clear auditory hallucination without drugs for the first time ever. I put myself to bed to lay & rest as I figure it has something to do with sleep deprivation. So perhaps take a prn sedative & try to get some sleep?

I think it's important to maintain in your mind that it is just a hallucination, it is not real, it is not true, it exists only in your mind & a mind in distress doesn't perceive things like it normally would.

I wasn't made inpatient when I told my Dr these things as I was aware, as you currently are, that it was a hallucination. You need IP if you are losing the ability to tell what's real & what's not or your feeling unsafe, barring that they can't keep you unwillingly. I hope this helps ((hugs))