Bone conduction is a method that takes the sound through the bones of the scalp to the inner ear.
Bone Conduction technology can be used by either individual with normal ear or suffering from deafness or hearing loss.
Bone Conduction is the reason why we hear our own voice differently when we talk and when we record and play it back. Our skull operates fewer frequencies than air, therefore, we consider our voices to be less and the frequency of your voice records more sound.
Bone conduction has rapidly become a critical asset for the treatment of hearing loss. While a new generation of cochlear transplant has had tremendous success in recent years, they rely on airborne driving and patients keep functioning from external to internal ears. For patients with severely damaged paths, such implants do not provide any solution.
How we usually Hear
Normal sound waves are actually small vibrations in the air. The vibrations travel through the air to our eardrums. Eardrums, in turn, decode these sound waves into a different type of vibration, which is obtained by the cochlea, also called internal ear. The cochlea is associated with our hearing nerve, which transmits sounds to our brain.
How it works
In the Bone Conduction listening devices such as headphones works as an eardrum which convert the sound waves to vibration and these vibrations are received by the cochlea via skull bone, then vibration is sent to the brain as an impulse signal via the auditory nerve. Therefore eardrums are not involved.
The legendary composer of the 18th century Ludwig van Beethoven was almost deaf in the discovery of the bone. Beethoven found a way to hear the sound of his piano by attaching a rod’s one end to his piano and clenching another end between his teeth. When he comes from the piano to his jaw, he gets the concept of sound vibration. This proved that sound could reach our auditory system through another medium without even use of eardrums.
Bone Conduction For Hearing Impaired Or Deaf
The use of bone conduction has greatly impacted those who are suffering from hearing loss and medical profession dealing with its treatment.
Although cochlear implant for hearing impaired have been extremely successful the implant relies on air condition of the sound wave and the ability of that wave to pass through to the inner ear. For that patient with damage middle ear canal, those sound wave could never reach inner ear making cochlear implant useless.
For those who are suffering from hearing impaired and deafness, Bone Anchored Hearing Aids (BAHA) is the best option they can rely on. BAHA is based on Bone Conducting principles. BAHA system is a titanium base system on which small sound processor is attached, which is implanted in the bone behind the ears. Once the sound system is activated it works on the same way as the conventional hearing aids but instead of sending a sound wave through the ear canal, vibration is sent via skull bone to the cochlea.
Bone conduction headphones are undergoing vibrations on the bone with enough power of music, which means that the person using the bone conduction headphones should be on the frequency range from 20 – 20,000 Hz.
But now, with an increase in technology some improvement has been made and more advance Bone Conduction headphone with better sound quality are now available as to meet customer demand.
Types Of Bone Conduction Devices
There are two types of Bone Conduction devices:
- The first one is the fixture which sticks out on the bone besides the ear.
- Another type of Bone Conduction device is fully implanted under the skin with the processor already attached to it using the magnet.
Benefits for People with Hearing loss
Most cases of hearing loss are due to damage to the eardrum. Since the bone does not use the eardrum, people with hearing difficulties will be able to hear clearly again with the conduction of the bone, provided their cochlea is in healthy and normal conditions.
Generally, hearing loss could be described in three categories. That would be conductive hearing loss, perceptive hearing loss and mixed hearing loss. Conductive hearing loss is associated with the faulty transmission of sound and is mostly due to damages to the eardrums. Bone conduction is able to aid a conduction hearing loss because a bone conduction device performs the role of the eardrums. Auditory nerves have a hearing loss with difficulty in feeling the vibrations in the cochlea. Bone movement is less effective for hearing impairment. For a mixed hearing loss, it is best to suggest a test in advance to know whether the bone movement can be a help for mixed hearing loss because it is individually different.