How does the hearing process work?

Hearing is one of the five senses and it refers to the ability to perceive sound by the auditory (hearing) system. Hearing is a complex process, and the ear is more intricate than it may appear.

The ear comprises three components:

  1. The outer ear
  2. The middle ear and
  3. The inner ear
FAQ Hearing Loss graphic

In physics, sound is energy that vibrates through the air in the form of a wave. A sound stimulus (e.g.: a person saying “Hello”) enters the outer ear and sets the ear drum in motion. The vibration of the ear drum in turn causes three little bones in the middle ear (the ossicles) to vibrate and thus pass this acoustic information on to the inner ear. The cochlea of the inner ear is arranged like a piano and converts this acoustic information into electrochemical information. This electrochemical information is then conveyed via the auditory nerve to the brain, where this information is interpreted.

What is hearing loss?

A hearing loss occurs when there is a breakdown, an abnormality or damage in one or more of the components within the auditory system. If there is a problem at the level of the outer and/ or middle ear (e.g.: a wax plug in the ear canal or a middle ear infection), this is referred to as a conductive hearing loss. A conductive hearing loss typically requires medical management from an ear, nose and throat specialist and is often temporary. If damage occurs within the inner ear and/or at the level of the auditory nerve (e.g.: degeneration of the cochlea caused by the aging-process, we refer to this as a sensorineural hearing loss. A mixed hearing loss occurs when there is involvement at the level of the outer and/or middle ear as well as the inner ear and/ or auditory nerve.

What causes hearing loss?

Both children and adults can present with hearing losses. A person may be born with a hearing loss (congenital), or it can be acquired later in life. Certain hearing losses are genetic, while others may develop from an illness or an injury.

Some causes of conductive hearing losses include:

  • Outer ear infection (otitis externa); also known as swimmer’s ear
  • Middle ear infection (otitis media)
  • An infection of the mastoid bone; the spongy bone positioned behind the ear (mastoiditis)
  • Trauma (e.g.: a blow to the side of the head affecting the outer and middle ear)

Some causes of sensorineural hearing losses include:

  • Noise-induced hearing loss
  • Hearing loss caused by certain medication that is toxic to the ears (ototoxicity)
  • Genetic hearing loss associated with certain congenital syndromes
  • The aging process

What to do when a hearing loss is suspected?

If you feel that your hearing “isn’t what it used to be” or if you are experiencing difficulty hearing, particularly in a noisy environment, it is highly recommended that you have a hearing assessment conducted by an audiologist.