A Guide to Deafness
22nd Jul 2020
The Oxford Dictionary defines ‘deaf’ as ‘Lacking the power of hearing.’ The Cambridge Dictionary defines ‘Deaf’ as ‘Unable to hear, either completely or partially’.
Both these small phrases raise interesting aspects of deafness. The first raises the point that hearing is power. Those of us with good hearing are likely to take it for granted but when hearing is restored, either through medical intervention or the use of hearing aids, hearing can have a positive effect on an individual.
The other pertinent point is that it is all a matter of degree – ‘completely or partially’ – and this is an element of hearing loss which is too often misunderstood and which this article seeks to address. The million-dollar question is ‘At what point does it matter’? The answer to this is, ‘when the quality of life is affected’.
An experienced audiologist will be able to assist you with identifying when this line is crossed and discuss possible solutions. Just as we benefit from wearing prescription glasses when our vision becomes impaired, hearing aids can assist us when we don’t hear as loudly or as clearly as we need. Ensuring the correct prescription is used and that the technology is programmed and fine-tuned correctly is essential.
Hearing well enables us to:
- Communicate with each other accurately and in a relaxed way, without having to strain, or mishear.
- Enjoy close relationships and emotional bonds through complex language nuances such as jokes
- Identify which direction speech is coming from so we know who is talking
- Immediately locate the speaker’s face for additional information
- Hear environmental activity so we know if someone is approaching, what the weather is doing, or if a car is passing
As our hearing becomes impaired, these skills begin to reduce proportionately.
Reasons for Deafness
Permanent Hearing Loss
Some of us are born without hearing and some are born with a lower than average hearing ability. Our ability to hear can also be lost due to infections, viral attacks, reaction to drugs, physical trauma, emotional trauma, strokes, hormonal imbalance and the ageing process.
Temporary Hearing Loss
This can occur when sound waves are prevented from travelling through the ear to the sound receptors. Reasons for this could include conductive issues, a temporary threshold shift after loud noise exposure, excess ear wax, or general head congestion.
Your audiologist will check carefully for causes during the initial hearing test, and offer solutions to resolve the issue where possible.
Hearing tends to reduce gradually, so the deterioration often goes unnoticed at first. This is why regular hearing tests are so important, especially after age 55.
Degree of Deafness
As deafness is classed as having below ‘normal’ hearing ability, we have to first understand what normal is.
Normal human hearing is the average volume at which young people, with no history of ear problems, can hear a range of frequencies. This level is acute enough to be aware of what is going on in our environment and also to follow speech with ease. Anything below this is classed as a hearing loss from mild through moderate, then severe and then profound.
The most typical type of hearing loss is where you still hear some noises at a normal volume, usually background noises, however, speech has become unclear. This can make hearing loss difficult to detect or accept as some quiet sounds can still be heard – but only in some frequencies.
During a hearing test, the hearing ability of both ears is measured and put on a chart of volume and frequency called an audiogram. The right ear is illustrated as red circles and the left as blue crosses. Good hearing is at the top of the chart at all frequencies.
The charts below show the test results for:
- Normal hearing
- severe to profound hearing loss
- partial hearing loss – in this example low tones can still be picked up easily but the ability to detect high frequency is very poor.
(To assist you in reading the charts below remember that red circles are for the right ear and blue crosses for the left.)
1. Normal hearing
The yellow area represents the volume of speech at its various frequencies.
Both right ear (red) and left ear (blue) are above the volume of speech. The patient will hear all speech easily
2. Severe to profound hearing loss
The grey banana shape represents the volume of speech at its various frequencies.
Both the right ear (red) and left ear (blue) are below the volume of speech. The patient will hear some loud sounds but he won’t hear speech without hearing aids.
3. Partial Hearing Loss
This is a hearing loss with normal low frequency and poor high-frequency hearing levels. Both the right ear (red) and left ear (blue) are normal in low frequencies and poor in high frequencies.
This person will know someone is talking, however, struggle to understand what is said. They may need to see the speakers face and avoid background noise when having a conversation.
It is important to remember there are different degrees of deafness, partially and permanently. It is normal for our hearing to slowly deteriorate after the age of 55. Usually, this affects our ability to hear certain frequencies, rather than volume. If you discover you are having trouble when conversing and these difficulties are affecting your quality of life and conversational skills, then it may be time to speak to an Audiologist. They will be able to carry out an Audiogram to discover where you struggle to hear and offer the correct solution for you.