Hearing Loss

Loss of hearing usually occurs gradually over time, and the effects are often not noticed until communication becomes difficult. Often, it is the person or people closest to the one with the hearing loss who first notice the signs.

These include:

  • Asking for repeats more often than normal
  • Not responding when spoken to from behind
  • Mis-hearing of information, eg fifty, instead of sixty
  • Turning the TV up louder than normal
  • Trouble hearing the phone or doorbell from a distance

Other indications that hearing may be a problem can be more subtle:

  • Watching faces more intently for visual cues
  • Beginning to withdraw from conversations
  • Choosing not to attend family or social gatherings
  • Relationships may begin to be eroded

The longer hearing impairment is neglected, the more difficult it is to cope with the psychological impact. Those with hearing loss are slowly becoming “detached” from the world of sound, and the earlier they seek to do something about it, the easier the return to normal communication patterns.

Don’t wait. Help is available!   Start by having your hearing properly assessed.

Causes of hearing loss

The most common causes of acquired hearing loss are:

  • Noise (37% of hearing loss in Australia)
  • Ageing
  • Infections/ viruses/illness
  • Ototoxic drugs
  • Trauma
  • Ear-specific diseases

When describing hearing loss, we generally look at three attributes: type of hearing loss, degree of hearing loss, and the configuration of the hearing loss.

Types of Hearing Loss

Hearing loss can be categorized by what part of the auditory system is damaged. There are three basic types of hearing loss: conductive hearing loss, sensorineural hearing loss, and mixed hearing loss.


Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones, or ossicles, of the middle ear. Conductive hearing loss usually involves a reduction in sound level, or the ability to hear faint sounds. This type of hearing loss may be able to be medically or surgically treated.


Sensorineural hearing loss occurs when there is damage to the inner ear or cochlea (sensory) or to the nerve pathways from the inner ear to the brain (neural). Sensorineural hearing loss not only involves a reduction in sound level, or ability to hear faint sounds, but also affects speech understanding, or ability to hear clearly.

Sensorineural hearing loss cannot be medically or surgically corrected, however hearing aids generally are a great help.


Sometimes a conductive hearing loss occurs in combination with a sensorineural hearing loss. In other words, there may be damage in the outer or middle ear and in the inner ear (cochlea) or auditory nerve. When this occurs, the hearing loss is referred to as a mixed hearing loss.

Degree of Hearing Loss

Degree of hearing loss refers to the severity of the loss. This is typically measured on a graph called an audiogram.

Audiogram demonstrating hearing levelsThere are six categories that are typically used to describe the patient’s thresholds, or the softest intensity that sound is perceived:

  • Normal = 0 dB to 20 dB
  • Mild loss = 20 dB to 40 dB
  • Moderate loss = 40 dB to 60 dB
  • Moderately-severe loss = 60 dB to 75 dB
  • Severe loss = 75 dB to 90 dB
  • Profound loss = 90 dB or greater

Configuration of Hearing Loss

The configuration or shape of the hearing loss refers to the extent of hearing loss at each frequency and the overall picture of hearing that is created. For example, a hearing loss that only affects the high frequencies would be described as a high-frequency loss. Different patterns of hearing loss will affect how it impacts on the person, especially how he or she hears the speech sounds.

Other descriptors associated with hearing loss are:

Bilateral versus unilateral

Bilateral hearing loss means both ears are affected. Unilateral hearing loss means only one ear is affected.

Symmetrical versus asymmetrical

Symmetrical hearing loss means that the degree and configuration of hearing loss are the same in each ear. An asymmetrical hearing loss is one in which the degree and/or configuration of the loss is different for each ear.

Progressive versus sudden hearing loss

Progressive hearing loss is a hearing loss that becomes worse over time. A sudden hearing loss is one that has an acute or rapid onset and therefore occurs quickly, requiring urgent medical attention to determine its cause and treatment.

Fluctuating versus stable hearing loss

Some hearing losses change – sometimes getting better, sometimes getting worse. Fluctuating hearing loss is typically a symptom of conductive hearing loss caused by ear infection and middle ear fluid, but it also presents in other conditions such as Meniere’s disease.

Congenital or acquired hearing loss

Hearing loss may be present at birth (congenital) or may occur or develop at a later time (acquired).

Pre-lingual or post-lingual

This refers to whether the hearing loss was present before a child has fully developed speech, or occurred after the development of speech.