Deaf Children Australia provides information sheets for deaf and hard of hearing children and young people and their families on a range of subjects. Information Sheets are copied onto pages in plain text so they are able be translated in your web browser. To translate a page, please use the yellow Translate tab at the bottom right of the screen. To download an information sheet in PDF format, click the PDF button and save the file.
Types of hearing loss
There are different types of hearing loss:
• Conductive hearing loss
• Sensorineural hearing loss
• Mixed hearing loss and
• Auditory Neuropathy
Conductive hearing loss
Occurs when sound waves do not reach the inner ear. There may be a blockage or issue in the external or middle ear. This can result in the sound being unable to be conducted through the ear canal through to the eardrum, or from the eardrum via the ossicles (three bones) of the middle ear to the inner ear.
Conductive hearing losses do not cause the hearing to be lost completely but there is a loss of volume. Sounds may be quiet but there is no distortion.
Common causes of Conductive hearing loss are:
· Wax in the external ear.
· Build-up of fluid in the middle ear preventing the ossicles (three small bones) from vibrating.
· A hole or tear (perforation) in the eardrum
· Structural differences in the development of the outer or middle ear
· Damage to the small bones in the middle ear
· An infection in the middle ear
· A blockage in the Eustachian tube meaning that air cannot move into the middle ear.
Ways to improve hearing:
· Hearing devices including tailored devices such as bone conduction hearing aids, bone anchored hearing devices and middle ear implants
Video on Conductive hearing loss:
Sensorineural hearing loss
Sensorineural hearing loss is in the inner ear or auditory nerve. This occurs when there is a problem with the sensory (hair cells) and/or neural structures (nerves) in the inner ear (cochlea). With this type of deafness, there are problems with the cochlea (damage or malfunction of the air cells in the cochlea) or the nerve, which carries sound to the brain.
Sound waves activate the tiny hair cells in the cochlea to vibrate and release chemical messengers that stimulate the auditory nerve. The auditory nerve consists of many nerve fibres that then carry signals to the brain, which are then interpreted as sound. While sensorineural hearing loss usually involves damage to the tiny hair cells, it can also result from damage to the auditory nerve. Some people call this “nerve deafness”.
Sensorineural losses can range from mild to profound. Both the volume and clarity of sound are affected. Sometimes sound can be heard but it may be distorted.
Sensorineural hearing loss is the most common type of permanent hearing loss.
Common causes of sensorineural hearing loss are:
· Premature birth
· Certain pre-natal infections
· Lack of oxygen during birth
· Genetic factors
· Use of certain medications that damage the ear (ototoxic)
· Illnesses, such as meningitis, rubella, measles and certain autoimmune disorders, amongst others
Ways to improve hearing:
· Assistive technology and hearing devices like a cochlear implant
Video on Sensorineural hearing loss
Mixed hearing loss
Mixed hearing loss occurs when both Conductive (issue with the outer or middle ear) and Sensorineural (issue with the inner ear) hearing loss is present. The Conductive hearing loss may be permanent or temporary, but the sensorineural hearing loss is permanent.
Video on mixed hearing loss:
Auditory Neuropathy is when the auditory nerve is unable to transmit the signal from the cochlea to the brain. The brain then has problems interpreting the sound that the cochlea has detected. Often the brain has problems with processing the sound information including speech and where sounds are coming from.
The hearing loss can vary from normal to profound, hearing levels can fluctuate. Understanding speech when there is background noise is particularly difficult.
Common causes of Auditory Neuropath loss are:
· Lack of oxygen or jaundice at birth
· Neurological conditions.
Ways to improve hearing:
· Assistive technology can sometimes help reduce the effects of auditory neuropathy.
Unilateral Hearing Loss (Deafness in One Ear)
A unilateral hearing loss means a hearing loss in one ear only. The other ear has normal hearing. Difficulties associated with this type of loss are locating the source of sound and hearing in background noise. Children with unilateral hearing losses may also have problems in the classroom,
both in relation to hearing and socialization. Teachers need to be aware of the hearing loss so that strategies can be put in place.
Progressive or Acquired Hearing Loss
Some peoples hearing will degenerate with age or the progression of a syndrome which affects that
persons hearing. Or through damage to the ear through an acquired source – eg: the use of in the
ear buds for amplification of music, or through industrial noise.
National Deaf Children’s Society www.ndcs.org.uk
This is an excellent website with lots of information on childhood hearing loss. It has a wealth of topics for families to explore.
Meningitis – www.ndcs.org.uk/information/childhood_deafness/meningitis/index.html
This is also from National Deaf Children’s Society and gives a good overview of meningitis in children.
This site has information relating to Ushers Syndrome
Ear Problems in Children
This site lists the common causes of ear problems in children.
Middle Ear Infections
This site discusses middle ear infections in children
Deafness: A Range of Causes
This site lists the causes of deafness
The videos in this information sheet are for general information. You should discuss your concerns and options for treatment with your Audiologist. DCA does not endorse Med El.