Friday, 17 September 2021

Listen up, what’s in your ears is pretty special...

Listen up, what’s in your ears is pretty special...

“MUSIC is like a dream. One that I cannot hear.”

The loss of hearing that Ludwig van Beethoven suffered towards the end of his life was cruel and his words illustrate just how much we rely upon our hearing to enjoy the world around us.

Our ears, unsurprisingly, are integral to the process of “hearing”.

This sense is one of which those who were born deaf simply have no concept. The set of channels, bones and nerve cells is able to convert vibrations from all around us into an almost indescribable entity in our heads.

To be fair, the really remarkable stuff all happens in the brain. What we hear as “sound” is merely the brain’s interpretation of what is happening in the physical world, much like what we see.

But let’s not forget the ears’ role in all of this. A sound is essentially vibration of air particles that travel in waves at high speed. If I drop a saucepan on the floor, it will create ripples in the air that spread out in all directions.

This wave of sound reaches the ear and is collected by the first section, the outer ear, where it is channelled inwards towards the eardrum.

As the air hits the eardrum, the ripples are conducted into three tiny ossicles (the smallest bones in the body) called the malleus, incus and stapes (colloquially known as the hammer, anvil and stirrup).

These are pretty special because they gradually reduce the amplitude of the vibrations, in effect scaling down the sound so it can be processed in ever-smaller regions.

The last of these bones is attached to another smaller drum that then transfers the vibrations into fluid which is contained in a tiny organ called the cochlea.

The walls of the cochlea are covered in tiny hair-like nerve cells which, when excited by the vibrations, convert them into nerve impulses which then travel via the vestibulocochlear nerve to the brain, where the magic happens.

This way of hearing sound is not the same throughout the animal kingdom. It is thought that the bones of our mammal ears were once incorporated into the jaws of a common ancestor of ours and modern day reptiles.

Indeed, some reptiles, including snakes, use their jaws to “hear” sounds, while others, such as insects, use antennae to detect vibrations in the air rather than ears.

Such a delicate system is, of course, vulnerable to the louder sounds. Anything above about 85 decibels, for example, busy traffic, a motorbike or listening to music on full volume via headphones, will damage your hearing and the longer the exposure the worse it gets.

Damage mainly comes from destruction of the tiny neural hairs in the cochlea which are irreplaceable. It is therefore important to take precautions to reduce such exposure, for example, by ensuring that you use noise-cancelling headphones rather than turning your music up just to cancel outside sounds and not listening at more than 60 per cent volume). Ear protectors in noisy work environments are important.

A sure sign that you are damaging your hearing is the ringing sound that tends to be experienced after a loud concert. If you’re lucky, this will fade after a few hours but repeated exposure can cause tinnitus. This is a really unpleasant and often intrusive condition in which a sufferer will experience ringing in the ears all of the time when there is no obvious source.

The list of famous musicians who suffer from tinnitus includes Bono, Pete Townshend, Chris Martin, Neil Young and will. i. am.

Unfortunately, there is no known cure for this but, depending on how intrusive it is, there are measures you can take to introduce distractions and psychological techniques that help combat the depression which is often strongly associated with this complaint.

If you develop a one-sided tinnitus, it may be a good idea to get this checked out by your GP as sometimes there can be other underlying causes.

Probably the most common ailment we see in general practice when it comes to ears is infection. Any part of the body exposed to the outside world is vulnerable and the ear is no exception.

Happily, the vast majority of earaches are caused by viruses that can track up from the eustachian tube at the back of the mouth that helps equalise the pressure between the inner and outer ears.

If this gets blocked, you lose that ability and so the difference in pressure can become very uncomfortable, particularly if you travel on an aeroplane.

Most ear infections will be cleared up by the body’s own immune system after three to five days so otherwise healthy adults shouldn’t need to see a GP (even if you’re about to go on holiday) until after this. Your best first port of call is your pharmacist.

If, however, there is a lot of discharge coming from the ear or you are feeling feverish and shivery, it is worthwhile getting a check. Note also that children with ear infections should be seen more promptly.

Critically, and contrary to what seems to be an ongoing fashion, you do not need to clean your ears. The wax in your ears is there for a reason. It is a mixture of oil, sweat and dead skin cells which, as unpleasant as that sounds, help to collect the very things that might cause infection.

The wax brings these out as the skin of the ear canal gradually grows outwards, a bit like a natural conveyor belt. Just occasionally, wax can build up to excessive levels, causing a conductive hearing loss and it is at this point that we might be able to help out with some syringing or micro-suction.

You should not, however, be putting anything like cotton buds in your ears. All this does is push wax further in and irritate the skin of the canal, predisposing it to infection. Nothing smaller than your elbow is the rule!

The ear has one final trick up its sleeve. There is a separate part of each cochlea which forms a series of canals. It is here that the body derives its sense of balance.

These canals are filled with fluid that moves in one direction en masse as we ourselves move. This stimulates hair cells on the walls that send signals to the brain indicating we are on the move. If all is working well, it combines in the brain with visual information from our eyes to give us a sense of position.

If, however, there is a bit of loose material in the semi-circular canals that brushes against the hair cells independently of the direction of movement, this sends a lot of confusing signals that don’t match up with what we see. This can give rise to something called benign positional paroxysmal vertigo, which causes a nasty dizziness, often described as a sensation that the room is spinning or a feeling akin to being on a swaying boat. It causes nausea and vomiting and tends to be triggered by turning the head.

Fortunately, this is something that does eventually fade on its own but not before a period of fairly uncomfortable and enforced inactivity. Medications to help with the nausea are available and the only other “cure” is something called the Epley’s manoeuvre, which can be attempted by some GPs if symptoms are not abating naturally.

So the ear is a complex and valuable part of our lives. If you do have a feeling your hearing isn’t what it once was, don’t be afraid to get it checked. Hearing loss is unfortunately something that occurs frequently as we get older. There are hearing aids available now that can make a really big difference, not to mention their crucial role in placating the neighbours who have to put up with the TV volume set to maximum!

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