Hearing impairment happens when one or more parts of the ear aren’t working effectively. The ear is the first part of the hearing system. The outside part of the ear catches sound waves and directs them down the ear canal. The waves then cause the eardrum to vibrate.
There are two main types of deafness:
- Nerve deafness which is a hearing impairment in the inner ear. This usually means that the cochlea isn’t working effectively. Nerve or sensorineural deafness is permanent.
- Conductive deafness which means that sound can’t pass efficiently through the outer and middle ear into the inner ear. This is often caused by blockages such as wax in the outer ear, or fluid in the middle ear (glue ear). Glue ear is a very common condition, especially in pre-school children. Conductive deafness is usually temporary, but it can be permanent in some cases.
Very few deaf children have no useful hearing. Most deaf children can hear some sounds at certain frequencies and loudness, and with the use of hearing aids or implants they are often able to hear more sounds.