Hearing loss at age 7, 10 and 13--an audiometric follow-up study.

School children are regularly tested in Sweden at age 7, 10 and 13. We report the audiometric results of 2264 school children tested at these three ages. Audiometry was performed as hearing screening at 0.5, 1, 2, 4, 6, 8 kHz with a screening level of 20 dBHL. Unilateral hearing losses with one test frequency affected were most common and bilateral hearing losses were least common. The hearing loss was more common in boys than in girls at all ages. Hearing loss at 2 kHz in boys at age 7 were uncharged in most cases (13/17 boys still failing screening at age 13). High frequency losses were most common, particularly at age 10 and 13 and more prevalent in boys than in girls, suggesting early noise induced hearing loss as an etiology.