Want to see what schizophrenia is like? Here is a schizophrenia simulator. You need to wear headphones to get the full effect though, otherwise it wont work.
Hearing voices can happen when anyone goes into psychosis, not just with schizophrenia. This can happen when someone has schizoaffective disorder. When someone has a psychotic episode with bipolar or even severe depression. Post partum psychosis can also occur. It can also be triggered from PTSD and severe stress.
Hear is a video of Anderson Cooper trying a schizophrenia simulation.