Show Prevalence of Deal iiok. At least one porson in threw between the ages of ten and forty years is subject sub-ject to partial deafness. The great majority ma-jority of cases of deafness are hereditary heredi-tary and due to the too close consanguinity consan-guinity of the parents. Deafness) is more prevalent among men than among women because the former are more exposed to the vicissitudes of climate. It is thought that telephones tend to bring on deafness when one ear is used to the exclusion of the other. |