Epidemiology of Hearing Loss

Epidemiology no longer concerns itself only with infectious diseases. Now it deals with the commoner non-infectious diseases in a population. In epidemiology, we deal with populations and this is the centre of the problem.Data on more than 30 000 cases of hearing loss were statistically analysed for the period 1966–1971. The number of males was higher than that of females in spite of the fact that, in the population, there is an inverse ration. The ratio of males to females increased as a function of age.The most frequent diseases were presbyacusis noise-induced hearing loss, sensorineural hearing loss of unknown origin, the different forms of chronic otitis and the consequence of these (cicatrisation, adhesive process, tympanosclerosis).The grades of hearing loss were determined in the different pathological processes and the distribution of these grades was calculated according to age.As regards sensorineural hearing loss, it was found that, among the patients older than 40 years, not only did the numbe...