Suite 10 Westmead Private Hospital
Westmead NSW 2145
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Academic appointment: Macquarie Univerisity
Hearing Loss
Hearing loss reduces quality of life, causing embarrasment, impairing social interactions, causing difficulty with employment and educational attainment. In childhood untreated hearing loss can prevent children from developing normal communication skills and reaching their full potential.
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The hearing pathway can be split into three regions
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The extenal ear: the pinna/auricle collects the sound and directs it to the ear canal, the canal has hairs and wax which prevent debris from entering the ear.
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The middle ear: Here the vibrations in the air (the sound) are converted into mechanical vibrations. The ear drum or tympinic membrane is a sheet of skin which vibrates as the sound waves strike it, this movement is transmitted to a connected series of bones (the ossicles) which act like a piston or level increasing the mechanical movement.
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The inner ear: Here the mechanical vibration is converted into electical impulses which are sent to the brain and will be interpreted as sounds. The Cochlea is a fluid filled organ lined with tiny hair like nerve endings. These tiny hairs are hinged at the bottom and when waves travel through the cochlear fluids the hairs are tipped, opening gates at the bottom and allowing electical currents to flow into the hearing nerve.
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Types of hearing loss
Senosrineural hearing loss: This is the most common form of hearing loss, here the Cochlea is usually the organ which is damaged. Usually the tiny hair/nerve cells are damaged resulting in a loss of "volume" and also of "clarity" in the system.
Conductive hearing loss: Damage to the ear drum such as a perforation (hole), fluid collecting in the middle ear space (tympanic cavity), or damage to the earbones (ossicles) can prevent the sounds entering the ear from being efficiently transmitted through to the inner ear. Damage here reduces the "volume" of the signal. Often surgical solutions are avaialble for this type of hearing loss, although hearing aids or implants can also be useful.
Mixed hearing loss: Both sensorineural and conductive loss can exist at the same time and can combine causing what is known as a mixed loss.
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Limitations of hearing aids
Understanding an audiogram
Although hearing aid technology is very good these days it cannot restore your hearing to its original condition, it is an aid to your hearing which should provide you with significant benefits in a variety of listening situations.
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Even if the hearing aid is appropriately chosen and well fitted you still may not hear as clearly as you would like, particularly in very noisy situations.
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Damage to the inner ear or Cochlea can cause difficulty hearing even when a hearing aid makes it audible.
Because of Cochlear damage the is often abnormal growth of loudness, meaning soft sounds are too soft but loud sounds are too loud. Sensibly set hearing aids can help with this problem.
Hearing loss in the Cochlea entails a loss of clarity of speech as well as a loss of loudness. As this is due to a loss of sensory cells in the inner ear it is difficult for hearing aids to overcome all of this problem
Speech is harder to follow at speed (temporal resolution).
The most common problem reported by those with hearing loss is that speech is hard to understand when in background noise. Hearing aids often have noise reduction strategies included. These are improving with newer aids.
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Although hearing aid technology is very good these days it cannot restore your hearing to its original condition, it is an aid to your hearing which should provide you with significant benefits in a variety of listening situations.
​
Even if the hearing aid is appropriately chosen and well fitted you still may not hear as clearly as you would like, particularly in very noisy situations.
​
Damage to the inner ear or Cochlea can cause difficulty hearing even when a hearing aid makes it audible.
Because of Cochlear damage the is often abnormal growth of loudness, meaning soft sounds are too soft but loud sounds are too loud. Sensibly set hearing aids can help with this problem.
Hearing loss in the Cochlea entails a loss of clarity of speech as well as a loss of loudness. As this is due to a loss of sensory cells in the inner ear it is difficult for hearing aids to overcome all of this problem
Speech is harder to follow at speed (temporal resolution).
The most common problem reported by those with hearing loss is that speech is hard to understand when in background noise. Hearing aids often have noise reduction strategies included. These are improving with newer aids (see the services and devices page for further information about these technologies).
What's in a name?
Hard of hearing, deaf, and Deaf.
Some of those with difficulties hearing prefer the term "hard of hearing" to hearing impaired or other similar monikers. As you will notice on this website Audiologists switch between terms frequently.
When used with a capital "D" Deaf usually refers to those in the Deaf community, those whose first language is sign (in Australia known as AUSLAN) as their main language.
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Generally, although deaf is used colloquially to refer to those with any type of hearing loss or impairment, it is not preferred by the hard of hearing community.