Altogether 153 (60%) out of a sample of 253 people aged 70 years and over living in their own homes were found to have impaired hearing when tested by pure-tone audiometry. This is almost twice the prevalence found in all other studies, in which deafness was assessed clinically or by self-reporting. The prevalence of deafness increased with age. Evidence of organic brain syndrome (dementia), as determined by questionnaire, was present in 39 (16%) out of 245 respondents, and of depression in 82 (35%). Dementia and depression were both age related. An apparent association between deafness and dementia was shown to be due to age alone. A significant relation between deafness and depression was independent of age and socioeconomic state. The use of audiometric techniques of assessment established that an association exists between deafness and depression that is not simply a function of differential reporting reflecting the emotional state of the respondent.