There is no definitive answer to this often posed question. We have many examples of people with what appears to be very mild hearing loss, struggling to comprehend, when compared with more moderate hearing loss. A lot of these can be explained by the ability to process sound, which can be affected by cognitive ability, age, health issues or other auditory related morbidities.
The first thing we should all consider is having a baseline hearing test regardless of age, which can be used as a benchmark of our hearing ability through life.
The following explanation will help you make the decision to have your hearing tested, sooner rather than later, and to help you understand when hearing aids may be required.
How is hearing loss defined?
Hearing loss is the inability to hear sounds, either partially or totally and can occur in either ear or more commonly in both. It is generally a gradual process of deterioration but can be of sudden onset which must be treated immediately and preferably within the first 24 hours. Total or profound hearing loss is termed anacusis and is the total inability to perceive sound, though this word is rarely used medically.
|Hearing category||Hearing ability|
|Dynamic range (healthy)||20Hz to 20KHz|
|Considered ‘normal hearing’||0-20 dB HL|
|Considered hearing loss||Loss of 25 dB HL in one ear (from base level)|
A healthy ear can typically hear from 20Hz to 20KHz and this is called the dynamic range.
The speech range is from 500Hz to 6KHz though, for fidelity and timbre it is beneficial to hear beyond this and useful if the dynamic range is at least 10KHz.
If an individual can hear between 0-20 dB HL (Decibel hearing level) across the speech range, then hearing is considered normal. dB HL is the sound pressure level in decibels and absolute normal is 0 DBHL across the speech range. A person is considered to have a hearing loss if there is a diagnosed loss of 25 dB HL in one ear.
There are three categories of hearing loss, sensorineural, conductive and mixed:
|Type of loss||Meaning|
|Sensorineural||Nerve loss, usually a loss of inner or outer hair cells in the cochlea, or central processing disorders|
|Conductive||Problem or inability to transfer sound waves through the outer and/or middle ear|
|Mixed||Combination of both sensorineural and conductive loss.|
What causes hearing loss?
There is quite an exhaustive list of causes and as with many health issues, we have a mixture of some control and no control over them.
The most obvious cause is ageing but alas, we have no control over that. We are born with our full complement of hair-like cells in the cochlea, the organ responsible for hearing. The longer we live, the more of these hair cells die or are worn out and our dynamic hearing range narrows. Once we start requiring sounds to be louder below 8KHz it can be said a hearing loss is present.
Presbycusis is the ageing process of hearing and is the most common cause of hearing loss amongst he elderly. But, by far the most common cause which we do have control over, is noise exposure. The World Health Organisation recommends that young people limit exposure to loud sounds and listening to personal audio players to only one hour a day. Listening to very loud sounds or being exposed to loud industrial noise causes trauma to the hair cells in the cochlea and they die, never to return.
Other causes of hearing loss are, genetics, infections, birth complications, trauma to the ear, ototoxic medication, chemical toxins, certain infections during pregnancy, poor diet and central or auditory processing disorders.
Approximately half of global hearing loss could be prevented through public health intervention like immunisation, correct care around pregnancy, avoiding unprotected ears in loud noise and avoiding certain medications.
What are the different levels of hearing loss?
Hearing loss is categorised as:
- mild if 25 to 40 dB
- moderate if 41 to 55 dB
- moderate-severe if 56 to 70 dB
- severe if 71 to 90 dB
- profound if greater than 90 dB
Knowing the signs of hearing loss
This is often contentious as we rarely admit that we have a hearing loss but there are signs of hearing loss which we will notice in others and if we apply them to ourselves, we may begin to realise our hearing is not what it was.
They may not respond to commands or your presence. Questions may need to be asked several times and you may notice you need to speak louder to get their attention. You notice them either looking in the wrong direction in response to a sound or looking around the room to try and localise where a sound is coming from.
They may answer incorrectly or not completely. They may not notice sounds or certain pitches of sounds from their toys. They could be restless, not sleep well or cry more often than normal, which could indicate an ear infection.
Difficulty hearing in crowds or at parties. This could include pubs and restaurants. People appear to mumble. Diction in films and TV programmes, not as clear as it used to be. You prefer the TV to be louder than anyone you are watching it with or they complain the TV is too loud. Muffling of speech and other sounds. You ask people to repeat things more than you used to. Difficulty hearing on the telephone. Not always hearing the telephone ring or the doorbell. Missing birdsong. Difficulty hearing soft or high pitched sounds.
Missing sibilants and consonants. Inability to hear rubbing your hands together at arms length in front of you. Not hearing the ticking of your watch or clock, especially those that you used to hear. Blaming inability to hear on poor acoustics, poor diction, too much environmental distraction.
Missing the punchline of a joke or story. Relying on others to fill in the bits you missed. Not hearing a play in a theatre like you did. You find it easier to hear a man’s voice than a woman or child. You feel more tired after concentrating during conversation.
Music is not as enjoyable as it used to be. You do not socialise as much because you are avoiding places where you may expect background noise. You have ringing in the ears. You find yourself relying on lip reading or trying to read people’ lips.
When does hearing loss require a hearing aid?
This can depend on how impactful a hearing loss is. It is well documented that one of the largest consequences of untreated hearing is the increased likelihood of dementia and the brain forgets how to hear. This is due to the missing stimulus that we all receive even when not in conversation. A quiet room is not so quiet when you really concentrate and start to list all the things you can hear.
We would always recommend regular hearing tests and advise to correct one’s hearing loss at the earliest opportunity to avoid many of the cognitive issues related to prolonged untreated hearing loss.
How much does personal preference play a part?
There is always the wish to acquire hearing aids that are invisible and that is perfectly natural. Fortunately, we are one of the few accredited Lyric centres in the UK which allows us to fit the tiny invisible Lyrics implants deep in the ear canal.
These devices give a very natural sound and being completely invisible and with no daily insertion or removal, or batteries to change, they are very desirable. Perfect for mild to moderate hearing loss.
For more significant hearing loss there are larger devices and with bluetooth connectivity allowing far more individual control to settings and volume, these are also very desirable.
How is hearing loss diagnosed?
The very first step of the journey is to take a detailed medical history and fill out a lifestyle questionnaire. This will help us identify if there is a potential cause of the hearing loss and also understand your needs and requirements. Next we use video-otoscopy to take images and check the health of the outer ear canal and tympanic membrane or eardrum. This will also indicate if it is safe to proceed with further tests.
We then determine how well you process sound by performing speech tests and recording your responses to a series of different word lists.
As the number one reason for booking a hearing test is trouble hearing in noise, we then perform what is probably the most important test of all, a speech in noise test. This is where a recorded series of sentences is played through headphones or ear inserts and you respond by repeating what you think that sentence is. The number of words correctly repeated is recorded. Each subsequent sentence has more background noise to replicate the real life situations you find yourself in. The results of all our speech tests give a percentage score of your ability to hear.
The next test is the main reason for booking in the first place, the audiometric test. This is performed in a soundproof booth or soundproof room.
A series of pure tones are played and a button is pressed by you everytime a tone is heard. This is done one ear at a time and the results plotted as a line on a graph called an audiogram. A further test is a bone conduction test to determine if the hearing loss is sensorineural or conductive and either will determine further tests to perform.
Depending on results, it may be necessary to conduct a tympanogram which measures middle ear function and is very commonly and regularly taken in the case of conductive and mixed hearing losses. A small probe is placed into the outer ear canal and once a good seal is acquired, gentle pressure and a tone are played into the canal and the response automatically recorded.
All of our fundamental tests may determine further tests or consultations are required depending on results and treatment plans suggested.
This is all done in joint consultation so we can be assured you fully understand the process and together we get the best possible solution for your hearing and obtain an improved quality of life.
What to do if you’re experiencing hearing loss for the first time?
Simply contact us to arrange a diagnostic evaluation of your hearing. It could be that you simply have a blockage like excessive ear wax and do not require hearing aids at all.
You can self refer and do not need to visit your GP first.
What if your hearing loss is the result of an injury?
If your hearing is the result of an injury, you may be entitled to compensation, especially if the injury occurred at your workplace. The first process is get your hearing tested and your ears examined.
We have all the necessary high-tech diagnostic equipment to ascertain what type and degree of hearing loss you may have and the correct solution for you.
Please do not hesitate to contact our hearing care specialists
Our team is on hand to offer you expert advice and to help you with your experience of hearing loss. From a consultation to tests and choosing the right hearing aid, we can help make the process a lot easier no matter your level of hearing.
Our hearing clinics are based in Horsham, Chichester and Seaford in the south of England and always welcome new patients. For details on how to best contact us, click here.
What our clients say
Two members of my family have just received excellent advice and treatment at the Chichester Centre.
My husband for ear plugs advice and my 12 year old son, who has been suffering with excessive ear wax building up for the past year or so and being told by GP that can do nothing except keep putting drops in.
Within 15 minutes he had his ears safely unblocked, using micro suction and washing, something the GP said was not available. My son is like a different child and can actually hear again.
Thank You!Mr J Llewellyn – Chichester patient