What is the hallucinations are just auditory? if it's left untreated is there a big possibility that the disease will be worsened?

YES: You should see a doctor to get checked out and possible referred to a psychiatrists for treatment. If you wait it will likely get worse and cause other problems. Deal with this now before it gets to be a crisis.

Hallucinations: of any kind need to be treated. These symptoms can erode the quality of life of the person involved. When treated life can improve. Peace and good health.