Hearing and deafness

How do we hear?

The ear is complex due to the process of evolution. The inner ear (cochlea) with it's sensitive hair cells is designed to hear in water(i.e. in the sea). The middle ear is made up of the eardrum, eustachian tube and the three smallest bones in the body. It is designed to help the cochlea to hear efficiently in air (i.e. on land). The external ear (the visible bit)helps us with the direction that a sound came from. Having two ears helps with direction too. Visit https://actiononhearingloss.org.uk/ for more details on hearing mechanisms.

How do we measure hearing?

Sound is measured by it's loudness measured in decibels(dB) and frequency (high or low note) measured in Hertz (Hz). Human hearing is normally between 0-25 dB and 32-12000 Hz. An audiogram in a sound proof room accurately measures hearing level for each note. A tympanogram measures the pressure in the middle ear i.e. our ability to pop our ears.


Are you deaf?

Your ability to hear depends on a number of factors:

1) The background noise (e.g. night club or quiet room)

2) Listening skills (the ability to concentrate)

3) Hearing level (the good function of the inner, middle and external ear)


You can only be considered to have hearing impairment(deafness) if you have a problem with your hearing level. Deafness is divided into two main types: conductive or sensory. Conductive hearing loss is caused by a fault in the external or middle ear and can often be cured by medical treatment. Sensory hearing loss is due to a faulty cochlea or nerve and is rarely curable; it usually requires a hearing aid.


Who can diagnose my deafness?

ENT surgeons and audiologists are both experts in diagnosing deafness. The audiologist supplies hearing aids and advice so is best for sensory impairment. The ENT surgeon prescribes medical and surgical treatments so is best for conductive impairment. They work together by referring the patients to each other.


Common causes of deafness


Wax protects the delicate skin of your external ear canal from harm. If it builds up or is pushed against the eardrum, it can cause deafness and discomfort. See the "Infection of the ear" page for treatment options.

Glue ear

Head colds and other nasal conditions block the eustachian tube and the middle ear fills with mucus.

Age related deafness

It is not the case that we go deaf with age. It is noise that slowly wears out our cochlea hair cells. People that have been exposed to lots of noise at work or play seem to age their hearing more quickly! The sensitivity of the cochlea to noise can vary between different families.

Perforation of the eardrum

Trauma or infection cause a perforation..


The little bones in the ear become fixed (stuck) in about2% of the British population causing a conductive hearing loss.