Hearing impairment is a common but serious problem affecting children of all ages. According to the Palo Alto Medical Foundation, roughly 2 percent of children suffer from some degree of hearing loss.

Hearing loss is a common problem. About 15 percent of U.S. adults say they have trouble hearing, reports the Centers for Disease Control and Prevention. Hearing loss is especially prevalent in older adults, with nearly 36 percent of people over 65 reporting difficulty hearing.

Psychosis refers to an impairment in an individual's ability to perceive and interact with his environment. Some examples of psychotic features include hallucinations (seeing, hearing, or feeling things that aren't there) and delusions (believing in things that aren't true despite evidence to the contrary).