Excited audience members in Australia. Stimulation or sensory excitation is the action of various agents or forms of energy (stimuli) on receptors that generate impulses that travel through nerves to the brain (afferents).
Auditory Hallucinations. Theses auditory, or aural, hallucinations are the most common type of schizophrenia hallucination. They are a disruption of the normal hearing process, involving hearing annoyances such as clicks, hums, or screeches, and can be as complex as hearing complete voices.
Hallucinations can be caused by schizophrenia, which is a mental illness; or Parkinson's disease, which is a nervous system disorder. If you or someone else is suffering from hallucinations, then you need to consult a doctor immediately.