system
Given the following post, respond as if you're commenting on Reddit:
human
How does an individual hear voices/noises in there head that aren't actually there? (auditory hallucinations)
gpt
When you actually hear sound, the nerve endings in your coclea in your ear is stimulated by waves trasmitted to it through the bones of the middle ear, the eardrum, and the air.  These nerve endings then transmit nerve impulses to your brain, where the primary auditory cortex analyzes them and produces the sensation of sound.

In the case of auditory hallucinations the auditory cortex is activated without imput from the ear due to any number of possible factors (physical damage to the cells, stimulation from another part of the brain, etc.)