There's a lot more to hearing than the part of the ear we can see! To learn more about how our ears interpret sound, let's answer the question, "How does hearing work?" by taking a quick trip through the ear.
First off, there's sound. sound travels in the form of vibrations. Hearing is really the process of interpreting those sound vibrations as meaningful information. A song, a voice, a gunshot, a sonic boom, or a snoring spouce: all these different sounds are just vibrations, traveling through the air. So how does the ear work to turn those vibrations into auditory information the brain can actually understand?
To begin with, the ear has three sections: the outer ear, the middle ear, and the inner ear.
The outer ear -- the part of the ear you can see -- catches and funnels sound vibrations into the ear. As sounds enter the outer ear, they cause the eardrum to vibrate, which passes the sound vibration on to the middle ear.
The middle ear contains three bones, called the hammer, the anvil, and the stirrup. The eardrum transfers sound directly to the hammer, which passes it on to the anvil, and then to the stirrup. All three bones are necessary to get the sound through the middle ear and into the inner ear.
The inner ear has two main parts: the vestibular labyrinth, which has to do with your sense of balance, and the cochlea, which is filled with fluid and lined with about 24,000 tiny hairs. When sound vibrations are passed into the inner ear, the fluid in the cochlea is stirred into waves, and all those tiny hairs lining the cochlea react by converting the waves into electrical impulses. Finally, those electrical signals follow the auditory nerve to the brain, where the sound is finally processed and understood.
So to put it all together: sound travels through the air as vibrations. The outer ear helps to catch those vibrations, channeling them through to the eardrum. Those vibrations are passed through the tiny bones in the middle ear, making their way into the inner ear. There, the cochlea's tiny little hairs transform those vibrations into electrical impulses. The impulses follow the auditory nerve to the brain, and bam: you're hearing a sound.
And all of that incredibly complex stuff is happening right inside our ears, all the time -- and it happens without us ever having to think about it! All those tiny, sensitive parts just hum away, doing their job of turning vibration into information, whether we're listen to our favorite tunes, or trying not to listen to our neighbor's tv blaring at 2am.
It's definitely safe to say there's a lot more to the ear than meets the eye!
Now that you know how hearing works -- and how complex and sensitive the insides of your ears are -- you might consider brushing up on your hearing protection know-how. If you're new to earplugs, we recommend starting with our Foam Earplug Trial Packs. They're a good (and very affordable) way to start figuring out which kind of earplugs works best for you, so you can start protecting your hearing and preserving your marvelous, sensitive, and complex ears.
Until next time, be safe and do the right thing.
--Tom "Dr. Earplug" Bergman
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