How Hearing Works

How does the ear work?

The ear is a complicated organ: it works as a receiver, amplifier and signal processor. The ear is made up of several important parts. These are:

  • The outer ear
    This part of the ear pulls together sound waves before they move through the auditory canal and on to the eardrum.

  • The middle ear
    The eardrum and the hammer, anvil and stirrup bones (also known as the malleus, incus and stapes) are found in the middle ear. The role of these bones is to move sound waves to the inner ear.

  • The inner ear
    Inside this area of the ear, sound waves are changed into electrical impulses by the cochlea. The cochlea is filled with fluid, and lined with small sensory cells. It transmits impulses to the brain, which in turn processes sounds that we hear.

Hearing Loss

To view Scanning Electron Microscope (SEM) Pictures of the structures of the ear, consult:
Ahlers-Hankey, V. & Chrisholm, ,J.  (Eds). Inside the body. Fantastic images from beneath the skin. 2006 . Cassel Illustrated.

What causes hearing loss?

There are two general types of hearing loss. These are:

  • Sensorineural hearing loss
    This occurs when the delicate hair cells in the inner ear or nerve pathway to the brain are damaged. Most cases of hearing loss are sensorineural, and usually requires the use of hearing aids.
  • Conductive hearing loss
    This occurs when there is an interference with the conduction of sound through the outer and middle ear. This can sometimes be treated with medication, although in some cases, hearing aids are required.

There are some common causes of hearing loss. These include:

  • Ageing
  • Noise exposure
  • Chronic conditions
  • Illness
  • Genetic factors
  • Medication
  • Nerve and brain conditions

What are the symptoms of hearing loss?

If you have noticed some of the following, you may be experiencing hearing loss:

    • You often miss parts of conversations
    • You have trouble hearing on the phone
    • People often tell you that you listen to the radio or TV too loudly
    • You sometimes have to turn your head to one side to hear a sound
    • You experience a common ringing sound in one or both ears (known as tinnitus)
    • You don't always hear everyday sounds, like the phone ringing


What can I do about it?

If you experience the signs of hearing loss, it is important to have a comprehensive hearing evaluation, so that your audiologist can recommend a treatment plan. Read more about hearing tests and how they work.