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.
Keep in mind that a person with dementia is trying to make sense of his or her world with declining cognitive function. A delusion is not the same thing as a hallucination. While delusions involve false beliefs, hallucinations are false perceptions of objects or events that are sensory in nature.