Hearing Problems

Sensorineural Hearing Loss

If a person cannot hear well and there is no problem in the outer or middle ear, the cause of the hearing loss is in the part of the auditory system responsible for the generation of tiny electrical signals in response to incoming sound waves, the cochlea, or in the auditory nerve or higher structures that transmit sound to the brain. This type of hearing loss is referred to as sensorineural.

Sensorineural hearing loss results from damage to or disorders of the inner ear, which includes the cochlea, eighth cranial nerve, and the cochlear nuclei. It is the most common type of hearing loss among adults and the most common cause of permanent hearing loss in children.

Sensorineural hearing loss may be congenital (present at birth) or acquired.

Congenital causes of sensorineural hearing loss include:

  • genetic anomalies and syndromes
  • birth complications such as asphyxia or anoxia
  • maternal infections such as rubella and cytomegalovirus (CMV)

Acquired (or adventitious) causes of hearing loss include:

  • noise exposure (in the workplace, or through recreational activities such as loud music, use of firearms, or power tools)
  • ageing (presbycusis)
  • Menière's disease (a medical condition that may also cause tinnitus and vertigo)
  • acoustic trauma (injuries caused by foreign objects pushed into the ear canal)
  • head and neck injury
  • abnormalities/disorders of the inner ear (perilymphatic fistula, large vestibular aqueduct syndrome)
  • ototoxic drugs
  • bacterial meningitis
  • acoustic neuroma (tumour on the auditory nerve)

Unlike conductive hearing loss, sensorineural hearing loss is almost always permanent. It is generally managed through aural rehabilitation, which may include amplification with hearing aids, cochlear or auditory brainstem implants, or an assistive listening device. In some instances, medical treatment may be required - for example, surgical removal of acoustic neuroma - but these cases are less common.


Further Reading:

1. Access Economics (2006). Listen Hear! The Economic Impact and Cost of Hearing Loss in Australia.

2. Department of Veterans' Affairs, Commonwealth Government of Australia (2003). Your Lives, Your Needs: findings from the 2003 survey of entitled veterans, war widows and their carers.

3. Katz J (Ed) (2002). Handbook of Clinical Audiology, Fifth Edition. Baltimore, MD: Lippincott, Williams, and Wilkins.

4. Mitchell P et al. (2002). The prevalence, risk factors and impacts of hearing impairment in an older Australian community: The Blue Mountains Hearing Study.

5. Silman S, Silverman CA (1997). Auditory Diagnosis: Principles and Applications. San Diego, CA: Singular Publishing Group.

6. National Council of Aging (1998). The Impact of Untreated Hearing Loss in Older Americans.

7. Williams W, Forby-Atkinson L, Gartshore G (2002). Hearing loss and the farming community. Journal of Occupational Health and Safety of Australia and New Zealand, 18(2):35-44.

8. Wilson D, Walsh PG, Sanchez L, Read P (1998). Hearing impairment in an Australian population: statistics based on a four-frequency average hearing loss greater than 25 dB HL in the worse ear. Centre for Population Studies in Epidemiology, South Australian Department of Human Services.