noise induced hearing loss

Another repost from my old website. Hope you find it interesting!

Structure of a human ear
Structure of a human ear

Last Thursday I sat at the back of a noisy bus on my way to the station. In my ears were ear buds playing music at my usual fairly moderate level. You can imagine my astonishment then when I realised that I could hear somebody else’s music playing. I took a look around the bus and realised that across the aisle on the other side of another person was a girl listening to thumping techno at volumes that to her must’ve sounded roughly like a 737 landing on her face.

Unlike the irritating clowns who whinge in mX (the free afternoon newspaper distributed on public transport) about iPod listeners’ music distracting them from their furious navel-gazing on their journey home from their dreary jobs, I have no particular problem with being able to hear someone else’s headphones. Since I respect my ears I wouldn’t listen so loud but whatever floats your boat I suppose. Rant aside, it did get me thinking about noise induced hearing loss. So I did a bit of reading, learnt some stuff and hope to enlighten you a little.

The image of the human ear to the right gives a basic overview of what a human ear looks like. Sound waves travel down the ear canal and cause the eardrum to resonate. This vibration is transmitted through the ossicles and into the fluid filled cochlea. Within the spiral-shaped cochlea are a large number of very fine hairs. Their arrangement is somewhat analogous to the keys on a piano where hairs toward one end of the cochlea detect high frequency sound and those toward the other end detect low-frequency sound.
Continue reading “noise induced hearing loss”