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The human ear is divided into three sections. The eardrum, which is also known as the tympanic membrane, separates the middle ear from the outer ear. The middle ear has three tiny bones known as ossicles. They consist of the malleus, incus, and stapes. The malleus connects to the eardrum and the stapes to the cochlea, which is a fluid-filled structure in the inner ear. Within the cochlea is a tiny but highly complex structure called the Organ of Corti, inside of which are tiny hair cells.
Sound waves are funnelled by your ear canal to the eardrum. When the eardrum vibrates in response to these waves, the vibrations are amplified by the bones of the inner ear and are then transmitted into the inner ear. This amplification is necessary because fluids in cochlea create a mismatch in impedance between the inner and outer ear.
To understand how this works – imagine being with a friend at the swimming pool. If you are both standing in the shallow end, you can hear each other quite clearly. However, if you go under water you will have a hard time hearing your friend even if his or her voice is quite loud. This is because the impedance of liquid is different from the impedance of air.
By amplifying the vibrations from the eardrum, the ossicles of the middle ear provide ‘impedance matching’ so sound is properly transmitted to the cochlea.
In response, the flexible hair cells bend and straighten. This converts the sound into electrical signals which can be interpreted by the brain, to which they are carried by the auditory nerve.
How sound damages your ear
Each part of the ear plays a vital role. Unfortunately, damage to these delicate mechanisms can cause hearing loss. For example, the eardrum is quite thin and can tear if sound waves are too powerful.
The tiny ossicles in the middle ear can also be damaged by loud, intense noise. While damage to either of these structures is serious, it rarely results in total hearing loss.
However, damage to the hair cells in the cochlea can result in permanent, irreversible hearing loss, particularly for higher frequencies.To protect your hearing, it’s best to avoid prolonged exposure to very loud noises, or those that are above about 85 decibels (dBs). A decibel is the unit used to measure the intensity of sound.
Noise-induced hearing loss (NIHL) can be immediate or it can be cumulative. A gunshot or explosion that occurs close to the ear can be painful and cause immediate hearing loss.
On the other hand, regularly visiting a nightclub or concert where the music is too loud or working in a noisy environment may not cause immediate damage, but over time the effects can add up and result in permanent hearing loss.
Tinnitus is the perception of constant noise or ringing in the ears. It is a neurological condition that can create significant distress and a reduction in the quality of life. Unfortunately, the brain mechanism causing the condition is still not fully understood.
Additionally, there is no medical test that diagnoses it, at least not in individuals. Cutting edge technology can potentially detect it in groups that suffer from the condition.
It is believed that tinnitus is normally caused by hearing damage. While the basis of the condition is not thought to be psychological, psychologically based treatments such as CBT can improve the symptoms.
Their aim is not to change the sound that the patient experiences, but to help him or her notice the sound less often. When they do hear it, the focus is on removing the negative responses that lead to suffering.
An argument can be made that, since there is no medical diagnostic for tinnitus, there is no proof that it is not a psychological condition.
The normal response to this is to point out that many medical conditions, both past and present, are not detectable by available tests. This just reflects the limits of such tests without providing proof of the underlying basis for any condition.
Image credit: Freepik
Earpieceonline, a supplier of radio earpieces to a large number of industries. They are constantly banging their drum (within safe sound levels) for protecting people’s ears within the workplace. This is a part of their guide to better ear health.