About 10 percent of the hearing impaired get musical hallucinations, and about 10 percent of the visually impaired get visual hallucinations.

Source: "What Hallucination Reveals About Our Minds." TED2009. Feb. 2009. Conference Presentation. Additional Information: This quote is from neurological anthropologist Oliver Sacks' 2009 TED Talk about Charles Bonnet syndrome, a condition in which visually impaired people experience visual hallucinations. In this quote, Sacks is explaining that a percentage of people who are hearing or visually impaired experience audio or visual hallucinations; the hallucinations do not occur as a result of any psychological condition, but as a result of their hearing or visual impairment. Watch the full TED Talk here: Oliver Sacks - What Hallucination Reveals About Our Minds

“What Hallucination Reveals About Our Minds.” TED2009. Feb. 2009. Conference Presentation.