Types of hearing loss
A variety of biological and physical processes can cause hearing loss, which can be either congenital (you’re born with it) or acquired (you get it later in life). There are four main categories:
Conductive hearing loss stems from problems in the outer or middle ear. It can be caused by earwax, an ear infection, a punctured eardrum, a build-up of fluid or abnormal bone growth.
Sensorineural hearing loss occurs when the part of the ear that changes sound into electrical information (the cochlea) and the part of the ear that sends that electrical information to the brain (the auditory nerve) is damaged. This type of hearing loss is usually permanent. It can relate to genetic factors or be caused by ageing, diseases or exposure to noise and chemicals.
Mixed hearing loss is due to a combination of the conductive and sensorineural varieties. For example, someone may have sensorineural hearing loss caused by ageing or a genetic condition, and conductive loss from a middle-ear infection at the same time.
Retrocochlear hearing loss occurs when the auditory nerve (1) itself is affected. Although sound is processed properly by the inner ear (2), the auditory nerve has difficulty transmitting it to the brain. People affected tend to have trouble listening in the presence of background noise