Why does hearing get worse with age?

Updated: Aug 2, 2018

The official term for age-related hearing loss is Presbyacusis: from the Greek presbys – old, and akousis – hearing. It’s also commonly referred to as high-frequency hearing loss or ski-slope hearing, due to the distinctive sloping shape on a hearing test graph.

How we hear

The inner ear contains the cochlear, which is our organ of hearing (it looks a little bit like snail’s shell). Inside the cochlear are lots of little hairs. These hairs beat backwards and forwards with sound vibration. This movement creates an electrical signal which is transmitted down the auditory nerve and to the brain.

The hairs in the cochlear are grouped into sections and each section is responsible for processing a certain pitch or frequency, of sound. Hairs in the outer swirl of the cochlear process high frequency sound and hairs on the inside of the swirl process lower frequency sounds.

What happens when we age?

The problem is wear and tear. These little hairs, because of all the beating back and forth, start to tire out and break over time. It is the breakdown of these hairs that causes the reduction in our ability to hear. The cochlear is no longer able to process certain sounds properly, and both the quality and intensity of sound is affected.

The good (ish) news is that not all of the hairs are affected equally or at the same time. It is the high-frequency hairs in the outer part of the cochlear that are affected first. Age-related loss is distinctive because the high-frequency hearing deteriorates first while the low frequency hearing stays intact for longer.

When does it start?

It normally starts to become evident around the age of 60, and it is believed that over 70% of 70+ year olds have hearing loss. However, age of onset varies depending on lifestyle and genetics, and it’s not unusual to experience age-related loss in your 50s.

What does age-related loss sound like?

High frequency speech consists of mostly sharper consonants, letters and sounds such as ‘s’ ‘t’ ‘f’ ‘th’ ‘k’. Low frequency speech consists of vowel sounds and deeper consonants such as ‘d’ ‘b’ ‘m’ ‘g’ ‘z’. High frequency speech-sounds tend to form the beginning and ends of words and are what give us the sharpness and clarity of speech.

A classic example uses the sentence ‘the cat sat on the mat’. If you take out the high frequency sounds you’re left with the following:

_he _a_ _a_ o _he _a_

It’s not really clear what it says. And this is what high frequency hearing loss is like. You know something has been said but because there’s no clarity to it, it’s hard to discern what has been said.

What are the signs and symptoms that I am losing my hearing?

Words sound muffled, like people are mumbling and not speaking clearly. You start to say ‘pardon’ or ‘what’ because you haven’t quite heard everything. You mishear words. You miss alarms like the beeping of the oven or microwave. You turn up the volume of the TV. You struggle more than you used to in groups of people and in background noise. Friends and family start to comment that you’re not hearing as well as you used to, or that you need a hearing aid.

How quickly does it deteriorate?

Age-related hearing loss occurs slowly over a number of years. Most people don’t even notice it happening because they adapt as it deteriorates. Audiology guidelines state hearing should be tested every 3-5 years, and in that time, hearing levels will only decrease by a few decibels, if any at all.

Some people cope better than others

You can have two people with exactly the same hearing loss on paper, but they can have completely different experiences. Sometimes this is to do with how long they’ve had the loss for – the longer they’ve had it, the more likely they are to have adapted. Age of onset is also a factor – the younger brain will have adapted better.

The environment they’re in plays a big role. If someone is mostly at home, normally communicates in a one-to-one conversation, and doesn’t have ambient sound in the background, it is a much more straightforward listening environment and therefore they are less likely to notice their hearing loss. Conversely, if someone is in a busier environments like an office and they’re having meetings, or their office is open plan and there are printers and computers and phones ringing and people chatting, they are far more likely to notice the struggle with their hearing when there is so much sound for their brain to process.

What can I do about it?

There is no medical cure for age-related hearing loss. In the same way our skin wrinkles, bones hurt, hair greys, eyesight deteriorates, so too does our hearing.

There is a theory that noise exposure contributes. The greater the intensity of sound we hear over time, the greater the damage to the hair cells is over time. So certainly noise protection throughout life is important – if you work in a noisy environment, always make sure you wear your ear protection. If you enjoy loud concerts, make sure you invest in ear plugs. If you’re an avid listener of music, be mindful of the volume you have it at (good noise-cancelling headphones help with this).

The other thing I recommend is to get your hearing tested regularly from the age of 60 onwards, about every 2 years is a good idea. It will keep you mindful of your hearing and get an idea of rate of deterioration. It also means you are more likely to get a hearing aid at the correct time.

Hearing aids are very important. They are as important as eye-glasses and yet we don’t have the same acceptance of them as we do glasses yet. As soon as your hearing starts to deteriorate, get a hearing aid. Even if you think things aren’t too bad, hearing aids are so small these days they’re hardly noticeable and the benefits are great. As your hearing sensitivity declines, the auditory neurons in the brain start to change and we don’t want this, we want the brain to be stimulated properly. Research is still looking at why this is so important but for example, hearing loss is a risk factor for dementia. If you have hearing loss and don’t get a hearing aid, not only will your cognitive function suffer, but it will also be much harder to get used to a hearing aid if you have left it too late.

As always, if you have any queries or comments, feel free to ask them in the comment section or you're welcome to contact me directly. Email info@earmint.com