The human brain during hallucinations This PET scan, taken at the moment a patient was having auditory hallucinations, shows heightened activity (yellow-orange) in Broca’s area, a brain region that helps people produce speech, and in the auditory cortex, the brain area that helps people hear sounds (Silbersweig et al., 1995). Conversely, the front of the brain, which is responsible for determining the source of sounds, was quiet during the hallucinations. Thus people who are hallucinating seem to hear sounds produced by their own brains, but their brains cannot recognize that the sounds are actually coming from within (Juckel, 2014).