Most people with healthy hearing don’t even think twice about what it means to have good hearing. Chatting with friends, listening to the sounds of nature, enjoying music or hearing warning signals – they take it all for granted.
It is only when hearing starts to deteriorate noticeably that we realise just how important good hearing is in our everyday lives. And how much we miss out when we no longer hear well.
Most of us know someone affected by hearing loss, as nearly 1 in 5 people live with the condition. This number increases significantly for people over 60 years to 1 in 2 people. Hearing loss progresses over time and it is best to recognise the signs early.
Quality of life can be significantly compromised for people with hearing loss and their families. The extent of the hearing loss varies too, from a mild to a profound hearing loss where loud safety signals may not be heard. More commonly it manifests as difficulty understanding speech, particularly in the presence of background noise early.
What Is Hearing Loss?
In contradiction to many people’s understanding, hearing loss is rarely similar to the effect of turning down the volume on a stereo. It usually affects different frequencies of sound by varying amounts. This can lead to conversations being difficult to follow – particularly in noisy environments where competing background noise “scrambles” speech and conversations. Not surprisingly, being able to follow conversations is the single biggest reason that people seek our help.
Types of Hearing Loss
Hearing loss can occur in either one of two ways, or a combination of both.
Conductive Hearing Loss
Conductive hearing loss occurs when the outer or middle ear is dysplastic or does not work properly. Consequently, sound waves cannot be efficiently conducted to the inner ear. In case of a temporary dysfunction, it is often possible to correct conductive hearing loss with surgery and/or treatment with medication.
Common causes of conductive hearing loss include:
- Injury of the outer ear itself
- Blockage of the ear canal due to ear wax (cerumen) or other small objects like food, beads or insects
- Infections of the outer or middle ear
- Perforation of the tympanic membrane
- Congenital deformities (e.g. Down syndrome, Franceschetti syndrome, Treacher Collins syndrome or Achondroplasia (dwarfism)
Sensorineural Hearing Loss
Sensorineural hearing loss is the most common type of hearing loss. It has its origin in the inner ear or along the auditory nerve. Most commonly, the damage occurs in the inner ear (cochlea).
In this instance, the hair cells in the cochlea are damaged and cannot transmit neuro-electrical impulses to the brain. Sensorineural hearing loss can be congenital (present at birth) or acquired after birth.
Common congenital causes include:
- Hereditary factors
- Viral infections
- Birth trauma such as anoxia
- Acquired causes include:
- Reactions to ototoxic drugs (damaging to the hearing system)
- Head injury
- Noise exposure
- Ear infections
- Other diseases
Mixed Hearing Loss
The transmission of sound can be blocked in multiple places along the auditory path. 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. An example of a mixed hearing loss may be 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.
Noise Induced Hearing Loss
Given the impact of noise, it is not surprising that 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 people are exposing themselves to noise levels that will lead to long-term damage to their hearing, including the use of personal stereo systems.
This diagram illustrates the time it takes to cause permanent damage to your hearing when you’re exposed to different levels and sources of sound.
What Can You Do to Make Listening Safe?
According to the World Health Organisation the duration of the exposure to noise is one of the key factors contributing to overall sound energy levels. There are ways to minimise the duration. It is advisable to:
- Have short listening breaks. When going to nightclubs, discotheques, bars, pubs, sporting events and other noisy places, take short listening breaks to help reduce the overall duration of noise exposure.
- Move away from loud sounds. At a noisy venue, stay as far away as possible from sound sources such as loudspeakers. Moving to quieter locations within venues can reduce the level of exposure.
- Limit the daily use of personal audio devices. While it is important to keep the volume down,limiting the use of personal audio devices to less than one hour a day would do much to reduce noise exposure.