understanding Hearing loss
Hearing loss affects 1 in 6 Australians, and 3 in every 4 people aged over 70 years. With an ageing population, hearing loss is projected to increase to 1 in every 4 Australians by 2050.*
Hearing loss can result from dysfunction of any part of the auditory system and can vary significantly in severity and associated hearing difficulty. Audiologists are qualified to assess your hearing and communication needs (see Hearing Assessment) and design a program to optimise your hearing abilities.
Types of hearing loss:
Sensorineural Hearing Loss
A sensorineural hearing loss is usually permanent in nature and occurs when there is damage to the cochlea (sensory) or auditory nerve (neural).
Gradual deterioration of the cochlea is most commonly caused by normal ageing and excessive noise exposure, but may be congenital (present at birth), or acquired as a result of trauma, exposure to ototoxic agents, disease or infection affecting the inner ear, progressive genetic conditions, or auditory neuroma.
There is rarely any medical treatment for sensorineural hearing loss. In most cases it can be successfully managed with hearing aids, assistive listening devices or cochlear implantation.
Conductive Hearing Loss
A conductive hearing loss usually occurs when there is blockage or damage to the outer and/or middle ear. The degree of conductive hearing loss varies and may fluctuate, but will never result in total deafness. Common causes are excessive wax, eustachian tube dysfunction, middle ear infection, glue ear, perforation of the eardrum and damage to the ossicular chain (e.g. otosclerosis or dislocation). It is common to have some degree of conductive hearing loss when you have a cold, due to eustachian tube dysfunction.
A conductive loss can often be treated by medical or surgical means. Where treatment is unsuccessful or contraindicated, the hearing loss can be successfully managed with hearing aids, assistive listening devices or implantable devices.
If both a sensorineural and a conductive loss occur together in the same ear, the condition is known as a mixed hearing loss.
Describing hearing loss:
Although many people talk about hearing loss in terms of percentage, it is not an appropriate or meaningful measure of hearing loss. Hearing sensitivity is assessed at many points across the frequency range of human speech, from low bass tones to high treble tones. It is very common for a person to have a different amount of hearing loss at different frequencies; therefore a single percentage value is virtually meaningless when describing the overall hearing loss.
Hearing loss is instead described in terms of the degree of impact it would have on a person's everyday life if it were to remain untreated or unmanaged (e.g. with hearing aids). The severity is indicated as 'mild', 'moderate', 'severe' or 'profound', as detailed below. The 'shape' or configuration of the hearing loss is also described using terms such as 'high-frequency', 'flat', 'notched', or 'steeply sloping', to indicate whether some frequencies are more affected than others.
Mild: 20-44 dB
You would have some difficulty hearing soft speech and conversations in noisy places but would manage in quiet situations with clear voices. People may sound like they are mumbling and sounds may be lacking 'clarity'. Hearing aids will assist most hearing problems in this range.
Moderate: 45-64 dB
You would have difficulty understanding conversational speech in quiet places and more so in the presence of background noise. The TV and radio would be turned up to help with speech understanding. Hearing aids will assist most hearing difficulties if speech discrimination is good and background noise is reduced as much as possible.
Severe: 65-90 dB
Normal conversational speech is mostly inaudible. Hearing aids will amplify many speech sounds to an audible level, although the clarity of speech heard is likely to be affected and visual cues will assist in understanding speech. Hearing aids are highly recommended and supplementary assistive listening devices and listening strategies would provide further benefit. A hearing implant may be appropriate if hearing aid use is not successful.
Profound: 91 dB +
There is great inconsistency in the benefit derived from hearing aids. Some can understand clear speech face-to-face in places with good auditory conditions with hearing aids, while others find it impossible. A cochlear implant may be more appropriate.
Note: Hearing loss is measured in percentage in specific situations, e.g. WorkCover testing. The decibels of hearing loss are converted via a recognized legal formula to create a "percentage of hearing loss", for legal purposes only.
A hearing problem can affect your ability to communicate with your loved ones, participate socially and fully enjoy life. It can also affect your educational and employment opportunities and leave you at risk of missing important warning sounds, such as traffic or smoke alarms.
Some early signs of hearing loss are:
Difficulty hearing soft sounds like footsteps, car indicators, whispers or softly spoken people.
Difficulty hearing in noisy situations or with groups of people, even if you have no problem in a quiet room.
You can hear, but not understand what people are saying – people mumble!
Difficulty understanding people if they talk while in another room, walking away, or behind you.
Listening for long periods of time is exhausting or you find yourself losing concentration.
You need the TV up louder than other people.
The presence of noise/ringing in the ears or head (tinnitus)