Had sleep test done, nothing, experiencing similar things with auditory hallucinations, sometimes upon awakening and sometimes episodically. I have no idea either but it happens to me every night without fail. I hope for you that it does not increase in frequency (it did for me, sadly) or severity (I almost jumped out my 2-story window onto pavement one night -- thought someone was in the house, was not comforted when two hours later I searched for them and found nothing). It is happening in the day and with balance, too, for me (earthquake feeling). So not just upon waking anymore. It is very scary at the moment, and I wouldn't wish it on anyone. I am so sorry you are having this happen. I hope to any powers that be that it does not get worse for you. I am at the end of my rope.

The first thing my psychiatrist suggested when I went in was a sleep study. I had one of those about a year ago, fine. I cannot do sleep studies every nine months. Good grief. They already think I have morgellons.

For you, since they are only at night, I would ask about a sleep study referral. That seems to be what people initially suggest, from my experience with a thyroid doctor and also with a psychiatrist. If you are on any new meds then make sure they know about this. If you are not having any kind of life-encapsulating thoughts like that the world works in certain magical/secret ways then it is probably not schizophrenia, which would be wonderful. But still.

ETA: This new thing I have sounds nothing like sleep paralysis. I can move. I have had sleep paralysis before, sans the fear, and just felt like, "well, I guess I'm dead. Oh well." I know that's not the norm for sleep paralysis, but it was always upon awakening. This is different. I do not think yours sounds like sleep paralysis entirely -- maybe a combination, but not entirely.