Hearing loss can generally be categorized into three types - Conductive, Sensorineural and Mixed.
A) Conductive: This type of loss is caused when something is preventing or reducing the transmission of sound from the outside world into the inner ear. That is, some type of blockage is occurring in the outer or middle ears. Some of the causes of conductive hearing loss include:
i. A severe build-up of wax
ii. Fluid or pus accumulation in the middle ear cavity
iii. A hole or perforation in the eardrum
iv. Abnormal growth of the bones (ossicles) in the middle ear (otosclerosis)
v. A foreign object is blocking the ear canal
These symptoms can often be treated medically. At times hearing aids are used to overcome the problem however it is recommended to seek the advice of your medical professional first.
B) Sensorineural Hearing Loss: This type of loss is the most common and is caused by problems within the cochlear or with the auditory nerve. Typically sensorineural hearing loss is irreversible and permanent. It reduces not only the intensity of the sounds heard but often distorts what is heard as well. The normal treatment for a sensorineural hearing loss is amplification through the use of hearing aids. Some potential causes of sensorineural hearing loss include:
i. Aging or presbycusis
ii. Prolonged exposure to loud noise (e.g.: music, construction work, gun fire, etc...)
iii. Genetic disposition or inherited hearing loss
iv. Viral infections of the middle ear invading the cochlear
v. Ossification or bone growth within the cochlear
vi. Exposure to an explosive noise
vii. Head injuries
viii. Use of certain drugs; for example drugs used in chemotherapy and radiation therapy as well as some antibiotics
ix. Sudden onset
x. Diseases such as meningitis and Meniere's
xi. Viruses such as mumps or measles
C) Mixed Hearing Loss: This is a combination of both Conductive and Sensorineural factors. Hearing aids can benefit persons with mixed hearing loss however it is recommended that they first seek advice from their medical profession before trying hearing aids.