Ear Trauma: Causes and Effects

Ear trauma is a term that covers any sort of physical damage to any part of the ear that is caused by an external force or event. It does not cover the effect of disease, infection or underlying illness. Major and minor traumas can affect the outer ear; these can result in serious injury and perhaps even loss of the pinna of the ear, but are unlikely to affect hearing. Trauma that impacts on the inner ear is less obvious, but is more likely to adversely affect the sense of hearing.

Injuries that Tear the Ear

Being in an accident at work or in a vehicle, being attacked and bitten by a dog, or sustaining a knife or gunshot wound are all major events that can tear and injure the ear. The most common ear injury is, however, usually self inflicted, when someone cleans their ear with a cotton bud or other blunt object. The cotton bud can easily be forced too far inside the ear canal, and can rupture and damage the ear drum. This can cause inflammation and pain, and can lead to an infection of the outer and middle ear.

Losing part or all of the pinna is physically disfiguring but only has a minor impact on hearing. It is now possible to be given an artificial pinna that is very realistic; a moulded ear shaped to match the remaining ear on the other side is implanted after the skin at the side of the head has been expanded and stretched. This is then used to overlay the ear implant, giving a natural looking ear covered in your own skin.

Impact Trauma

Accidents can also affect the ear, even if they do not tear the pinna. Falling or having a severe blow to the head can actually break the tiny bones in the inner ear. The hammer, anvil and stapes are all vital to hearing, so if they are damaged, it is common for partial or complete hearing loss to follow. Modern medical techniques can now detect any fractures of these small bones and they can either be repaired, or replaced by artificial bones.

Sound Trauma

The hearing can be damaged by exposure to very loud noises – this is described as acoustic trauma, or sound trauma. A sudden loud noise of an explosion may last only a few seconds but it can rupture the ear drum and cause major damage to the inner ear. Complete deafness may occur afterwards and this can be temporary or permanent. Noise of lower intensity can still be damaging if the ears are exposed to it over a long period. The classic example of this is the increase in hearing impairment in young people who have listened to music through tiny bud earphones at too high a volume.

While the hearing damage that results from being near to an explosion is immediate, the damage from chronic noise exposure is more gradual and it may be months or years before the hearing loss is noticed. The ability to hear higher pitched noises is usually lost first, and this can make it difficult to understand speech.

Why Does Noise Damage the Ear?

The mechanism by which listening to loud music over a long period of time damages hearing is now fairly well understood. The over-exposure to noise causes the hair cells inside the cochlea to become overstimulated. This makes them produced large amounts of free radicals, which build up and eventually result in the death of the cell. The longer the exposure and the louder the sound, the quicker this happens. When a significant number of hair cells are lost, the hearing starts to deteriorate.

Protecting the Ears

There is little extra that anyone can do to avoid an accident that might injure the external ear, or to prevent being near an explosion or work-related accident that damages the inner ear but preventing chronic noise exposure is more within our control. iPods and other music devices now come fitted with a control that limits the sound produced to a safe level, even at maximum volume. Even so, buying a set of speakers for an mp3 player when you are just listening to music at home and using the headphones for shorter periods of time when on the move is sensible.