You are born with 3500 inner hair cells for actual hearing, (and another 12,000 outer hair cells that help amplify sound) in each ear. Compare this to the 100,000 - 150,000 hair strands on your head, or the 10-15 million olfactory smell cells, or the 120 million rods and 6 million cones of your eyes. In this context, 15,000 hair cells in the ear is not a lot.   What you do with them is up to you! If you lost a strand of hair each day, it would take you between 273 - 410 years to become completely bald.  And that’s if you didn’t regenerate hair strands. But since most people lose and regenerate 50+ hairs every day, balding is not a problem.

If you lost one inner ear hearing hair cell a day out of your 3500, you would completely run out of hearing cells by the time you are 10 years old. (even if you include the 12,000 amplifying outer hair cells, you would be fairly deaf by 20 and completely run out by 42)  And these cells don’t regenerate. Fortunately, your hearing cells don’t die spontaneously every day.  It is usually an ACTIVE process that kills off hearing cells.

What causes you to lose your inner ear hair cells?  It takes some form of trauma to destroy off hair cells and their nerve fiber connections. By far, the most dangerous thing to hair cells is noise exposure, particularly loud sounds over 85 dB!

Every time you are exposed to loud music and it causes ringing in your ears, or a temporary deafness; you have damaged some hearing hair cells or their corresponding nerve fibers. It is like a tsunami of sound energy bouncing through your cochlea.  You might lose twenty or you might lose a few hundred or even a few thousand depending on how loud that noise is.

There are studies in animals that show that two hours of 100 dB noise at a given frequency can wipe out between 60% - 100% of their outer hair cell in that region.  And remember, these hair cells do not regenerate.

That means one loud concert or one explosive shotgun blast can make you deaf or partially deaf for the rest of your life.