In a longitudinal study, 2325 children were hearing tested at age 7, 10 and 13 with screening audiometry. The screening level was 20 dB HL. Approximately 75% of the children passed the screening level at all ages. Hearing loss was more frequent in boys than in girls at age 13 (16%:9%). The left ear was more commonly affected than the right ear. High frequency dips increased for boys with age, but not for girls. The increasing incidence of hearing loss for boys with age is probably due to noisy leisure time activities.