Simulate, but it isn't anywhere near perfect. Hearing voices is really just one facet of a facet of the disease. We have five senses and they are all going off constantly. So to get a true sense of what the hallucinations are like you'd need the earplugs, augmented reality goggles that are full field of view, probably some of those electrical stimulus pads, and something to create tastes and smells at random too.
There is a full symptom list over at https://www.nimh.nih.gov/health/topics/schizophrenia/index.shtml that goes into everything.
Schizophrenia reminds me of that quote "hell is other people". Well this is literally other people allofthetime, as your brain will not shut up. My brain will not shut up but at least the only voice I hear is my own (and music/memes that I remember, and that shuts off when I sleep). It's so bad and constant that you start to question your own reality, and then you start to question actual reality. They tell you you're worthless, they tell you you're famous, they tell you you're the son of god, they tell you you're a president, they make you doubt anything that ever is or was in your life and confirm things that have never actually happened as you're constantly gas-lighting yourself.
Finally, my favorite (disputed) schizophrenic artist: https://en.wikipedia.org/wiki/Louis_Wain. One of the images further down the page has a bunch of his works from different times in his life.
Hell I'm lucky that all I have to deal with is some mild autism.