An audiometric screening survey was conducted on a severely and profoundly mentally retarded population using noise-makers and pure tone audiometry. Of those tested with noise-makers, 83% gave an identifiable response to sound, 7% did not respond, and 10% were considered difficult-to-test. By contrast, 4% passed, 2% failed, and 94% were difficult-to-test using the audiometer. The resultant data were further analyzed as to age, sex, and medical classification. Females tended to be less responsive and more difficult-to-test. The age range 10-19 years appeared to be a critical period for responsiveness. It was concluded that audiometric methods other than standard pure tone audiometry would probably be better for a severely and profoundly retarded population. (Author)