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).
Voices are the most common type of hallucination in schizophrenia. Many people with the disorder hear voices. The voices may talk to the person about his or her behavior, order the person to do things, or warn the person of danger.
Hypnagogic hallucinations are often auditory or have an auditory component. Like the visuals, hypnagogic sounds vary in intensity from faint impressions to loud noises, such as crashes and bangs (exploding head syndrome). People may imagine their own name called, crumpling bags, white noise, or a doorbell ringing.