ABSTRACT
Deafness has a prevalence of 3.7-5.5 per 1,000. There are many causes of hearing loss, but they can be broadly divided into conditions causing a conductive deafness (where sound is prevented from travelling through the ear canal, or middle ear, by eg wax, fluid or a perforation) and sensori-neural deafness (where the problem is a dysfunction of the cochlea, the auditory nerve or higher centres).
