The noise of modern life is all around you – at work, at home, on the streets and in the classroom.
Continuous noise damages the tiny hair cells in the cochlea, which transmit neural impulses to the brain. Once these are damaged, they are unable to grow back. Over time, this makes it difficult to process noise and identify speech. Long exposure to very loud, or repeated noises may cause permanent hearing loss.
The worrying thing is that loud noise does not have to be an everyday occurrence for it to cause damage. Even being exposed to loud noise for a short time can cause temporary hearing loss (think about the last time you went to a loud concert or stood too close to fireworks).
There are usually no physical signs – the ears appear normal and there is no pain or dizziness.
Early signs may be:
• tinnitus (ringing in the ears) and slight muffling of sound.
• hearing no longer bounces back. Sounds have to be louder in order to be heard.
• loss starts in high frequencies and may spread to all frequencies if exposure continues.
This may be caused by sudden, single exposure to extremely high, loud noise such as a gunshot, or explosion near the ear. It is less common than other types of hearing damage.
Hearing loss caused by noise raises your hearing threshold – the degree of loudness needed before you begin to hear sounds.
Temporary threshold shift
In temporary hearing loss, most of the loss occurs in the first two hours of noise exposure. For example, industrial workers may not hear sound under 40 decibels by the end of day. Hearing usually returns within two hours of when exposure to the noise stopped.
Permanent threshold shift
If exposure continues for many months, the loss may become permanent.
Yes! No matter how old or young you are, too much exposure to loud noise can permanently damage your hearing and cause NIHL.
Always wear protection in high noise environments. If you think it might be too loud, it probably is!