Air Conduction VS Bone Conduction
We usually hear in two ways: by air conduction and bone conduction. Air conduction refers to sound from the outside carried by air waves from the outer ear and transferred to electrical waves in the inner ear. Bone conduction refers to sound conducted as subtle vibration along the bones to the inner ear housing the organs of hearing and balance. The sound vibration actually activates both the sense of hearing and the organ of balance. The vibration, in fact, is carried through the entire skeletal structure. Both ways of hearing help us gather sound from the environment and send it onto the brain where it is interpreted.
As we know, the densities of water and air are very different, but the densities of water and human tissue are very close. Therefore, when the sound propagates in water, it will be blocked by the air in the external auditory canal and cannot make the tympanic membrane vibrate, but it can cause the skull to vibrate. So in water we can hear through bone conduction.
How Does It Work?
Ludwig van Beethoven, the famous 18th century composer who was almost completely deaf, discovered bone conduction. Beethoven found a way to hear the sound of the piano through his jawbone by attaching a rod to his piano and clenching it in his teeth. He received perception of the sound when vibrations transfer from the piano to his jaw. This has proven that sound could reach our auditory system through another medium besides eardrums and the other medium is our bones.
For 40 years, bone conduction solutions have positively affected how people all over the world live their lives by using the body's natural ability to conduct sound. If you or your child have conductive hearing loss, mixed hearing loss or are deaf in one ear, also known as single-sided deafness, a bone conduction solution may be able to help. Problems with the outer or middle ear can restrict sound waves from getting to the inner ear through air conduction. Hearing through bone conduction can bypass these damaged, blocked or missing parts of the ear and deliver sound vibrations directly to the inner ear.
Bone Conduction Headphones
In bone conduction listening, the bone conduction devices (such as headphones) perform the role of your eardrums. These devices decode sound waves and convert them into vibrations that can be received directly by the Cochlea so the eardrum is never involved. The “sound” reach the ears as vibrations through the bones (or skull) and skin.
As for bone conduction headphones, users say they are very comfortable to wear and produce an adequate sound quality. Due to their open ear design, these headphones may be helpful for anyone with hearing loss and who wears hearing aids. They are also potentially helpful for tinnitus sufferers as they allow ambient sounds to enter the ear canal and may effectively act as a masking solution for individuals suffering from this condition.