The loudness of sound is measured in units called decibels. A decibel unit expresses the relative intensity of sounds on a scale from zero for the average least perceptible sound to about 100 dB, which is near the level most people find uncomfortably loud. Normal speech is around 50 to 60 dB.
When an individual is over-exposed to excessive sound levels, sensitive structures of the inner ear, such as hair cells, can be damaged, causing noise-induced hearing loss (NIHL).
Noise-induced hearing loss
Hearing damage can already begin at a continuous stress level of 85 dB. If you listen to loud music at a concert or on your MP3-player, for example, you may feel that you cannot hear so well afterwards. This happens because the fine hair cells of your hearing organ are temporary damaged. After a period of quiet, they recover. This is called a temporary threshold shift, TTS.
However, if you repeatedly subject yourself, over longer periods of time to extreme noise stress, these fine hair cells will become severely damaged with no chance of regeneration. This is called a permanent threshold shift, PTS.
Listening to loud music at concerts, discos or through headsets can be especially dangerous. The sound intensities through headsets, for instance, can easily reach 110-120 dB. A sudden loud explosive sound like a firecracker can also cause noise induced hearing loss.
People in loud work environments are particularly at risk. Construction workers, factory workers, airport-tarmac workers, and musicians should wear hearing protection.
What can you do?
The only reasonable alternative is prevention, so wear hearing protection! There are many possibilities from commercially available earplugs and earmuffs to individually fitted ear fittings with different filter systems.