An Audiometric Survey of the Incidence and Causes of Hearing Defects Amongst Draftees in the Vasa Military District, Finland, 1954–1968

Abstract

In the years 1954 and 1968, 992 and 1155 young men (19 years of age) were examined as part of their conscription examination for hearing defects. The survey was conducted in the military district of Vasa. The examination was performed with a tone audiometer (screening within the frequency range of 250–4000 cps at an intensity level of 20 dB TSO). Hearing defects were found in 12.10 and 11.26% respectively, with conductive defects 6.15 and 5.03% respectively, sensorineural hearing defects 5.95 and 6.23 % respectively. The incidence of adhesive otitis in the two series was 1.92% in 1954 and 1.56% in 1968. An obvious decrease of the incidence of chronic otitis media was noted, the incidence being 2.72% in 1954 against 1.13% in 1968. In 1954 a lasting binaural hearing defect of at least 40 dB IS0 in the better ear was found in 1.01% of those examined as against 0.51% in 1968. The cause of these lasting, bilateral, relatively bad hearing defects in 1954 in half the cases (5 out of 10) was either chronic otitis or adhesive otitis, while the rest of the cases consisted of sensorineural hearing defects: in 1968, 2 out of a total of 6 cases were caused by chronic otitis or adhesive otitis.