The ear consists of three parts: the outer ear, middle ear and inner ear.
Sound waves come into the outer (external) ear and hit the eardrum causing it to vibrate. Behind the eardrum, in the middle ear, are three tiny bones (ossicles) – the malleus, incus, and stapes. The vibrations pass from the eardrum to these middle ear bones. The bones then transmit the vibrations to the cochlea in the inner ear.
The cochlea contains tiny cells called hair cells which move in response to the vibrations passed from the ossicles. The movement of these hair cells generates an electrical signal that is transmitted to the brain through the auditory nerve. The cochlea converts the vibrations to sound signals, which are sent down the ear nerve to the brain, which we ‘hear’.
Causes For Hearing Loss
There are many possible causes of hearing loss. Typically these include:
- Natural ageing process
- Exposure to loud or constant noise
- Illness or complications at birth
- Toxic medication
- Ear infection
- Types of hearing loss
Conductive Hearing Loss
When the sound is not transmitted from the outer to the inner ear. Causes can include wax blockage and middle ear infections (otitis media) or perforations to the eardrum. In many cases this type of hearing loss will benefit from the use of a hearing aid system, sometimes in conjunction with medication and/or surgery.
Sensorineural Hearing Loss
Inner ear dysfunction. Such hearing loss is irreversible. Possible causes general wear and tear and noise exposure. Hearing instrument technology enable most patients to gain significant benefit.
Mixed Hearing Loss
As above both Conductive and Sensorineural.
A person who experiences hearing loss can have a range of tests, usually at a registered UK hearing aid dispenser or Hospital Audiology clinic. Examination of each ear is followed by an audiometric hearing assessment enabling the Hearing Aid Audiologist to determine if a hearing aid is required and if so which model would be most suitable.
Over 8 million people in the UK, all through the age ranges suffer from some form of hearing loss. Perhaps only a quarter of this number who would benefit from wearing hearing aids actually do wear them.