Seven items of activity related to patients' ability to handle behind-the-ear hearing aids (BE11/12) were investigated to establish the effects of age, sex and functional disability. One hundred and thirty-six patients were examined; all were first-time users of hearing aids. Over two-fifths of the sample had problems with manipulating the volume control and over a third had difficulty with inserting the earmould and changing the battery. For both men and women, the difficulties with the volume control and earmould were significantly associated with functional disability. Difficulties with these tasks were also significantly related to age and sex. Patients aged 75 years of age or more had greater difficulties than those who were younger and women had more difficulty than men.