Aural Health and Tinnitus
Aural Health and Tinnitus
One of the most important assets any musician has is their ears. Not only do they allow us to play with other musicians, keep check on our own playing, and (with some training) work out how to play songs using our ear, they are fundamental to actually experiencing music. It makes good sense then that we should be aware of our aural health, and how to avoid damaging our hearing. This article will cover some anatomy to explain how our ears work, what can cause damage to our ears, and what we can do to protect them.
How Does Sound Get From the Guitar to Our Ears?
When you pluck a string on the guitar, it vibrates a particular number of times per second depending on the tension (tuning) and length (fret) of that string. This displaces the air particles around the string at a particular frequency, causing waves of pressure to radiate out from the string. These pressure waves are what our ears interpret as sound. When the sound waves hit our outer ear, they are funnelled down into the ear canal until they hit the tympanic membrane (or eardrum). The eardrum is connected to three tiny bones called ossicles (these are actually the smallest bones in the human body). The sound waves cause the eardrum to move back and forth very quickly – at the same speed the string was vibrating. This causes the ossicles (tiny bones) to vibrate as well, and they stimulate the cochlear – a tiny organ deep inside our ear which translates these sounds into an electrical signal that our brain can understand. The cochlear is also what is normally damaged in progressive hearing loss.
There are two functions of this system: one, to funnel as much sound in from all directions, and two, to either amplify very quiet noises, or attenuate very loud noises. This second point is very important – if given the chance, your ears can adjust to constant loud noise by adjusting the position of your ossicles (tiny bones), reducing the force of the vibrations being sent through to your cochlear, partially protecting it from damage. This is why it is particularly harmful to hear a very sudden, very loud noise – your ears have no time to adjust.
What is the Cochlear?
The cochlear itself is basically a fluid filled tube coiled up like a tiny snail, and lined with special, tiny hairs called cilia. When sound vibrations are transmitted into the cochlear, depending on the frequency of the vibrations, certain cilia will be stimulated. These cilia are connected to neurons, and when stimulated, will transmit an electrical signal to your auditory cortex where your brain makes sense of the sound. The pitch of a sound is determined by where in your cochlear the cilia are stimulated – higher pitches will stimulate the cilia at the beginning of the cochlear, and lower pitches will stimulate the cilia towards the end of the cochlear. Loudness is determined by the number of cilia stimulated. If the vibrations travelling through the cochlear are very strong, then the cilia can actually break off. Unfortunately, unlike birds or amphibians, in humans they don’t grow back, so if you lose enough cilia at a particular location in your cochlear, you won’t be able to hear sounds at that pitch anymore. As the cilia for higher pitches are at the beginning of the cochlear, they are the most vulnerable to damage.
How Loud is Too Loud?
So as you can imagine, if you want to keep your hearing healthy, you’ll want to avoid loud noises, and particularly loud sudden noises. But how loud is too loud? According to the American National Institute on Deafness and other Communication Disorders (NIDCD), sounds of 75 decibels or less are unlikely to cause hearing loss. However noises at 85 decibels or louder can cause hearing loss. To give you an idea, here is a chart from the Australian Government National Acoustics Laboratories of common noise levels and how long you can safely be exposed to them:
What About in Lessons?
In lessons, we normally wouldn’t go any louder than the noise a vacuum cleaner would make, so you have nothing to worry about in terms of hearing damage during lessons. If you’re cranking the amp at home though, this may be something to think about. Exposure to sounds too loud for too long can result in acoustic trauma – that is, damage to your ears caused by sound. Acoustic trauma can result in both temporary and permanent noise-induced hearing loss – something none of us want.
What’s this Thing Called Tinnitus?
In addition to hearing loss, acoustic trauma can also result in Tinnitus – noise or ringing in your ears when there is no physical cause. Tinnitus is a symptom experienced due to damage to our hearing system, and can be made worse by anything that affects our hearing, such as an ear infection or excess ear wax. It can be diagnosed by your doctor. Treatment is dependent on the cause – for example, resolving an ear infection may clear up the Tinnitus. Unfortunately though, if the Tinnitus is hearing loss induced, there is currently no treatment or cure.
How Do I Protect My Ears?
What should be clear by now is that we need to look after our ears! Obviously, the best way to do that is to avoid situations where we are exposed to loud noises for a long period of time. That means keeping your amp at a reasonable level! Unfortunately though, there are situations we find ourselves in where we can’t help being exposed to loud noises – for example at work, or at a concert. In these situations we should really consider using hearing protection. Talk to your local music shop or ask your coach for a recommendation on hearing protection equipment. While over-the-head earmuffs will do the job, there are some much more subtle ear protection devices available which will attenuate the level of sound you’re hearing without compromising quality. While hearing protection can sometimes be cumbersome or inconvenient, it’s a small price to pay for protecting your ears.
Hopefully now you have a better understanding of how our hearing works, and how we can protect it. Our ears really are our greatest asset, and unfortunately if we don’t take care of them, they can become damaged beyond repair. To avoid this, be aware of noise levels and how long we can safely be exposed to them, and in situations where you can’t avoid loud noises, use hearing protection.
National Institute on Deafness and Other Communication Disorders
Australian National Acoustic Laboratories