Despite diagnosis being very pigeon-holed in today's medicine, its believed that Bipolar and Schizophrenia exist on the same spectrum of illnesses. A classical case of Bipolar would involve mood episodes only, but no psychosis; a classic case of Schizophrenia would involve Psychosis, but no mood problems. In reality, a lot of people with psychosis get depressed or sometimes even (hypo)manic and a lot of people with bipolar get psychotic features.
What you are experiencing is "psychotic features", i.e. whilst you are hullucinating right now, I can tell that you are still fairly lucid and still aware that this is not normal. A diagnosis of either Bipolar Disorder with psychotic features or Schizoaffective Disorder is possible. This is nothing to be ashamed of, but its certainly something that you should speak to your psychiatrist about.
I never heard voices outright per se. But I had some psychosic features. I had delusions of grandeur when I was Manic; I believed that I was the King of England. I had delusions of persecution (Paranoia); I believe my mother and my friends were all part of a conspiricy to manipulate and brainwash me. And I would see flashing lights in my field of vision.
It would help if you were to tell me more about your state of mind right now.
Are you manic, depressed or stable right now? Do you experience any Paranoia, delusions, disordered thought processes, or other types of hallucinations (visual, touch, taste, smell)? Have you been taking your medication regularly and if so what type of med do you take?
Regardless, my advice would be go and get help ASAP, and if you get on the right meds it can stop you from ever going full-blown Psychotic. People who manage to stop this problem in its early stages, go onto do a lot better in life than those that don't. If you are not already, you should be using an Antipsychotic. If you are on one, look into getting the dose/type adjusted. Frankly, if you ask my opinion, Antipsychotics are a lot better than Lithium/Valproate against BP, they are just as effective at treating mania and offer protection against psychosis and don't cause as many physical side effects, unlike Lithium/Valproate.