Have you ever wondered why you can hear higher pitched sounds under water than you can on land? Preliminary research conducted by the U.S. Navy has an explanation for why that is, and it has everything to do with… our bones!
The way you hear on land is very different from how you hear while submerged. Above water, humans can only hear between 20 and 20,000 hertz. While submerged, we can hear sounds up to 200,000 hertz. On land, sound travels through air conduction (sound waves travel through the air). These sound pressure waves cause tiny disturbances in the air and make the three little bones in your middle ear vibrate, which in turn causes sensory cells in your inner ear to send an electrical signal to your brain, which in turn interprets the sound and assigns meaning to it – a dog barking, an ambulance siren, a child crying, a hearty laugh.
But under water, humans don’t hear using these networks. The U.S. Navy study found that humans hear under water through bone conduction, rather than air conduction. With bone conduction, certain frequencies bypass the outer and middle ear and travel instead through the mastoid – the bones that sit just behind each ear at the lower part of the skull.
Because the mechanism for hearing under water is so different from hearing above it, hearing health researchers are excited. Why might this be? Think about this – a conventional hearing aid device uses air conduction to amplify sound that travels through the ear canal and the ear drum. Because the ability to hear higher frequencies is usually the first to go when it comes to hearing loss, understanding the role of the mastoid in hearing higher sound frequencies (bone conduction) will help hearing health specialists develop new technologies to diagnose hearing loss, and subsequently create hearing aid devices to treat it on a whole new level.
Additional research will need to be done on the role of the mastoid and hearing health, but one thing is certain – technology is on our side when it comes to treating hearing loss. Perhaps one day we will even be able to reverse it.
Your hearing is just as important as all of the other aspects of healthy living. At Sandia Hearing Center we will help you keep your hearing fit and strong for years to come. Call us today at 719-634-6260 or just stop by and say hello. We would love to meet you!