Research has clearly shown that loud noise causes damage to multiple structures in the ear. It can have serious effects on the hair cells within the ear, the tympanic membrane (or eardrum), and the nerves that feed auditory signals to the brain. This damage can result in either temporary or permanent hearing loss. Here is some information on how this happens so that you can avoid this sort of damage.
Temporary or Permanent Hearing Loss.
Hearing loss can severely impact someone’s quality of life. It can result in the inability to hear and therefore communicate clearly and can also negatively impact the ability to understand environmental sounds. Hearing loss can be the result of damage to the nerves that that carry information on sounds or damage to other structures in the inner ear. This damage may very well be temporary. However, where the damage is severe vital structures within the ear can be damaged beyond the ability of the body to self-repair. In cases like this, the hearing loss can be permanent.
One of the most common causes of damage to the cochlea (the inner ear) is loud noise. Even a single exposure to very loud noise can cause damage, as can prolonged exposure to above-average levels of sound. Loud noise can also damage the delicate hairs in the inner ear by overworking these structures. These cells may then be killed off. The hearing loss is progressive. The longer the exposure to loud noise, the greater the damage. The harm to the delicate structures in the inner ear may even continue after the noise has abated. Damage to the inner ear, or especially the delicate auditory neural system is by and large permanent. As a side point, you may be interested in seeing ”what panels absorb the most noise?”
Damage to Inner Ear Hair Cells.
Most people are born with around 16,000 cochlear hair cells. These cells are responsible for allowing the brain to detect and interpret sound. Hearing tests will measure damage once it has affected between 30% and 50% of these hairs. By the time the damage is measurable, those hair cells may be beyond repair.
People leaving a concert featuring loud music or even those who have been exposed to loud machinery will notice that their hearing has been adversely affected. Hearting will be muffled and they will experience problems in hearing whispers or people talking softly. Another common effect is a ringing in the ears. In most cases, a normal hearing will return within a short period – typically hours or days. Hair cells usually bend to cope with these loud sounds (like wheat in a field exposed to high wind) and will return to their normal orientation within this time.
However, in extreme cases, a large number of these hair cells may be damaged – and some will experience cell death at their roots. Repeated exposure to loud noise makes the problem worse and hearing loss will impact the person’s ability to understand speech, especially in areas where there is excessive ambient/environmental stimulus from noise. If the loss continues the hearting loss will persist even in a quiet environment.
Nerve Damage to the Ear.
Aside from damage to the delicate hairs in the inner ear loud noise can also damage the auditory nerve that carries signals to the brain. Again, early damage may not be revealed by a hearing test. This is termed ‘hidden hearing loss. It will also result in difficulty understanding speech in noisy environments. The effect is cumulative and will affect how well you can hear as you age. It is a contributing factor to how quickly your hearing loss will progress even once your exposure to loud noise has been limited.
The Mechanics of Hearing.
Our ability to hear is the result of vibrations that reach our ears. These are commonly called sound waves. Our brain interprets these waves as speech, music, environmental sound, and many other sounds.
The Outer Ear.
The outer ear acts as a funnel, collecting and focusing sounds. These sounds then travel through the ear canal onward to the inner ear and eardrum.
The Middle Ear.
The eardrum then vibrates and directs those vibrations to three very small bones in the middle ear. These structures then amplify the sound waves which travel onward to the inner ear.