Understanding hearing loss
Quality of life can be significantly compromised for people with hearing loss and their families. Social and physiological impacts include:
- Decreased workplace effectiveness and income
- Withdrawing from noisy social situations
- Feelings of isolation
- Strain on personal relationships
- Increased risk of early onset dementia
The extent of the hearing loss varies too, from a mild to a severe hearing loss where loud safety signals may not be heard. More commonly it is manifested as a difficulty with word understanding, particularly in the presence of background noise.
Conductive hearing loss results from a problem with the passage of sound through the outer ear and/or middle ear. Some common examples include:
- Excessive cerumen (earwax) in the ear canal
- Perforation of the eardrum
- Middle ear infection with fluid build-up
However, conductive loss accounts for only 10% of all hearing losses, and they range from mild to moderate in severity. The good news is that conductive hearing loss can often be medically treated, and in many cases, hearing can be completely restored.
Symptoms of Conductive Hearing Loss
With conductive hearing loss, the overall volume of sound is reduced and you are finding it hard to hear. Signs of conductive hearing loss may include:
- Turning up the volume on the television or radio
- Asking people to repeat what they say
- Hearing in one ear better than the other
When volume is sufficiently increased, clarity and understanding are usually intact for someone with a conductive hearing loss. Other symptoms may also be present, such as ear pain, drainage from the ears, or a feeling of pressure or a blockage.
Hearing loss that originates in the inner ear is referred to as sensorineural hearing loss or, in laymen’s terms, “nerve deafness”. The vast majority of hearing losses are sensorineural losses, and common causes include:
- Genetic factors (i.e. hearing loss can run in families)
- Excessive noise exposure – either sudden or prolonged
- Changes in the inner ear due to ageing
Less common causes include:
- Reactions to ear-toxic medications
- Auditory nerve tumours
- Conditions acquired prior to birth (congenital)
- Infections such as meningitis and mumps
- Kidney disease
- Vascular disease
Each cause can lead to damage to the sensory hair cells or nerves. Once damaged, the hair cells can’t repair themselves nor be medically treated. Therefore, 90% of hearing loss cannot be cured, however can be addressed by appropriate hearing device fittings.
A sensorineural hearing loss can be of any degree ñ mild, moderate, severe or profound. In more than 95% of cases involving sensorineural hearing loss, hearing aids or cochlear implants are the recommended course of treatment.
While the overall volume of sound may be reduced, the clarity of sounds or voices is also affected. People with sensorineural hearing loss will often hear people speaking, but can’t always understand all the words, even when the volume is adequate. Music may also sound distorted, leading to decreased enjoyment.
The symptoms of sensorineural hearing loss may include:
- Turning up the volume on the television or radio
- Asking people to repeat what they have said
- Perception of people mumbling or not speaking clearly
- Lack of clarity when listening to speech
- Difficulty hearing in noise
When a hearing loss occurs from conditions in the inner ear as well as the outer and/or middle ear, this is known as mixed hearing loss.
Sound levels that can cause permanent hearing damage. An example of a mixed hearing loss maybe someone with inner ear damage due to exposure to noise in their workplace over many years, who also currently has an infection that has led to a fluid build up in the middle ear.
While the ageing process is a major contributor to hearing loss, it is certainly not a condition reserved for the later stages of life. Studies have shown that exposure to noise is estimated to be a contributing factor in around 37% of cases of the condition and interestingly, around 50% of Australians with hearing loss are still of traditional working age (i.e. under 65 years).
- Other contributing factors of hearing loss include:
- Infection or injury (17.1% of cases)
- Born with hearing loss (4.4% of cases)
- Other causes (16.8% of cases)
Not surprisingly, given the impact of noise, males are considerably more likely to have hearing loss than women, including being twice as likely to have a moderate to severe hearing loss.
These days, people are more aware of the damage that noise can do to their hearing. This is illustrated through mandatory provision of ear protection on work sites and within factories. Nevertheless, every day millions of Australians are exposing themselves to noise levels that will surely lead to long-term damage to their hearing, including the use of personal stereo systems.
This graph shown here illustrates the time it takes to cause permanent damage to your hearing when you’re exposed to different levels of sound.
