Hearing impairment covers a broad spectrum of disability from mild difficulties with hearing to profound hearing loss. It can occur in children and adults. Speech and language acquisition may be affected by hearing impairment to various degrees depending on the degree and consistency of the hearing impairment.

How We Hear

The human hearing system is made up of three parts: the Outer Ear, the Middle Ear and the Inner Ear.

  • The Outer Ear collects the sounds which travel down the Ear Canal. The sound moves from the Ear Canal to the Eardrum which is a thin membrane of skin. When the sound hits the Eardrum it causes the Eardrum to vibrate. These vibrations are then transferred to the Middle Ear.
  • The Middle Ear consists of the three smallest bones in the human body – the Hammer,the Anvil and the Stirrup. These bones vibrate and pass the sound along to the Inner Ear.
  • The Inner Ear contains the Cochlea and the Semicircular Canals. The Semicircular Canals contain fluid and small hairs which move as the sound waves pass through the fluid and help the body to maintain balance.
  • The Cochlea also contains fluid which vibrates as the sound waves pass through it and changes the sounds into nerve impulses. The nerve impulses are then sent to the Auditory Nerve which passes the information onto the brain which processes the sound and allows us to hear and maintain our balance

What causes hearing impairment?

There are many different causes of hearing imparment. Some people have problems in the outer or middle ear, these are conductive problems. These people can usually be helped surgically, or with a good hearing aid.  Other people have problems in the inner ear because the vital hair cells, which should pick up the sound are damaged or absent, this is sensori neural hearing loss.

Otitis Media (“Glue ear”)

A common condition affecting hearing in childhood is “glue ear” which falls into the domain of conductive hearing loss. Glue ear is a painless condition in which thick, sticky fluid collects behind the eardrum. The fluid blocks the middle part of the ear and can cause impaired hearing. It usually affects children and is also known as

  • Chronic otitis media with effusion (OME)
  • Secretory otitis media
  • Middle-ear effusion

What Happens?

The thick fluid prevents normal movement of the small bones in the middle ear that are necessary for hearing. Glue ear is common in children because of the nature of their eustachian tubes, the tubes that connect the ears with the back of the throat. Children with Down Syndrome and Cleft palate are more prone to glue ear. Different kinds of fluid may be present behind the eardrum, ranging from a yellow liquid to a thick, white material that resembles glue (hence the name, glue ear).

Left untreated, glue ear can:

  • Cause temporary hearing loss
  • Contribute to delayed speech development in young children  ( as they can’t hear speech clearly)
  • Affect a child’s behavior and educational progress
  • In rare cases, cause permanent damage to hearing

About half of all cases of glue ear will resolve on their own within three months. About 90% of cases resolve within six months. It is important to have the condition evaluated by a Doctor, because in the time it may take to resolve on its own, glue ear may affect a child’s speech development or behaviour. Having glue ear is like listening to the world with both fingers stuck in your ears (try it!).

Children with glue ear cannot always hear everything that is said to them but young children may not be able to explain the problem. Signs of glue ear include irritability, and behaviour difficulties. The child may also want the TV volume high. They may also leave off the ends of their words as they cannot hear the whole word.  Any child who appears not to be hearing well should be evaluated by a Doctor and have a hearing test.