You Hear Through Your Hair

By Hearing Professionals

No, not the hair on top of your head, but through the hair cells in your inner ear. Let's say the teller at your bank asks “Checking or savings?” The sound of the teller's voice is first picked up by the pinna. This is the part of the outer ear that you can see, and it is mostly made of skin and cartilage.

The pinna works like a satellite to direct the sound into your ear and to help you figure out if the sound is coming from in front of or behind you. The sound travels through the pinna, down the funnel like ear canal, to your eardrum. Once the sound hits your eardrum, it will cause the eardrum to vibrate.

Just behind the eardrum there is a small space which contains three very small bones, this is called the ossicles. These are the smallest bones in your body, and they work almost like a gong with a microphone attached.

The eardrum first vibrates the hammer, or Malleus, which then strikes the Anvil, or Incus. The hammer and anvil are the gong and mallet; they transfer the sound through to the final (and smallest) bone, the Stirrup, or Stapes. The stirrup acts as a microphone attached to an amplifier. The amplifier in this case is the cochlea. When the vibration of sound passes through the hammer to the anvil then vibrates through the stirrup, the fluid in the cochlea starts to move and vibrate.

Inside of the cochlea, there are around 15,000 microscopic hair cells. These hair cells sense the movement in the cochlea, then catch and carry the sound to the auditory nerve. The auditory nerve sends the movements and vibrations to the brain, which then interprets the sounds we are hearing.

The hair cells in your ear are extremely sensitive, and unlike the hair on your head, they do not grow back. Once that hair is gone, it's gone for good. And there are many ways that your hair cells can be damaged. The most common reason why hair cells die is over exposure to loud noises.

Over exposure to loud noise can cause permanent damage to your hearing, but it is 100% avoidable. If you are a farmer, motorcycle enthusiast, hunter, police officer, musician, sports fan, or parent to screaming children, protect your hearing, because unlike the hair on your head, your hair cells can last a lifetime.