Common age group for otosclerosis is

Otosclerosis, more aptly called otospongiosis, is a primary disease of the bony labyrinth. In this, one or more foci of irregularly laid spongy bone replace pa of the normally dense enchondral layer of the bony otic capsule.Age of onset. Hearing loss usually stas between 20 and 30 years of age and is rare before 10 and after 40 years.Ref: Hazarika; 3rd ed; Pg 177