Conductive hearing loss results from a blockage of the outer ear, or a reduction of movement in the middle ear. Common causes include wax buildup in the ear canal, perforated eardrums, or damaged ossicles. Perhaps the most common cause of conductive hearing loss is middle ear infection. 80% of all children have at least one middle ear infection with fluid build up by their sixth birthday. The majority of these infections heal without causing any lasting damage, but they can cause temporary hearing loss and a delay in language and speech development. In cases of long-standing infections, complications can arise which cause damage to the middle ear (the eardrum itself, and/or the ear bones), resulting in permanent hearing loss.