Bone conduction is a relatively new trend in headphones targeted primarily at athletes. The technology is so different from regular headphones that many wonder if it could be helpful for deaf people. So, does bone conduction work for people with hearing disabilities?
Bone conduction works for types of hearing loss and deafness associated with the outer and middle ear. Hearing aids for these types of deafness work on the principle of bone conduction, and bone conduction headphones can enable certain deaf people to listen to music using the same method.
There are numerous variables at play, and it all depends on the type of hearing loss you have and, in some cases, any surgery that you underwent. Only a certified medical practitioner will be able to say for sure. But what determines if bone conduction will work for a particular type of hearing loss? Let’s study the different kinds of deafness and see how bone conduction could help.
Different Types Of Deafness
We must examine how hearing works before understanding the different types of hearing loss and how bone conduction can affect each.
Our ears consist of three main parts: the outer, middle, and inner ear. The outer ear is the outer ear that we can see, along with the ear canal, which captures sound waves (vibrations in the air) and passes them through to the middle ear.
The middle ear contains the eardrum and three little bones: the Incus, Malleus, and Stapes. As sound passes through from the outer ear, the vibrations pass into the eardrum, which in turn vibrates against the bones, amplifying the vibrations somewhat.
These vibrations pass into the inner ear, which consists of the cochlea and auditory nerve. The cochlea contains fluid and tiny hairs. As the bones vibrate, the fluid also vibrates, which bends the little hairs. These release a chemical when they bend, and the more intensive the bend is, the more chemicals are released.
The auditory nerve detects these chemicals and converts them into electronic signals. The brain receives the signals and interprets them as sounds.
It’s an immensely intricate process, and if any part of it is interrupted, damaged, or destroyed somehow, it leads to hearing loss. With this in mind, let’s look at the three primary types of deafness.
Sensorineural Hearing Loss
Sensorineural hearing loss is basically any type of deafness that affects the inner ear. It’s commonly associated with the cochlea, and most often occurs gradually, particularly as people age. The hair cells inside the cochlea weaken, which means they can’t bend and release chemicals as efficiently as they used to.
This type of hearing loss also occurs when you listen to music at high volumes too often since that also weakens the hair cells.
Conductive Hearing Loss
This is a problem that affects the outer or middle ear. It’s less common than sensorineural hearing loss, but it could still happen due to disease, injury, or other factors. The eardrum and the three bones are the parts most commonly affected to cause conductive hearing loss.
This generally means that, even though the cochlea and auditory nerve are working as they should, the sound vibrations cannot travel from the outer ear to the cochlea, limiting the person’s hearing ability.
Mixed Hearing Loss
When you have both inner and middle ear damage, doctors diagnose you with mixed hearing loss. For example, if you suffered an injury that damaged the three bones and the cochlea, it’s mixed hearing loss.
How Bone Conduction Works For Deaf People
Bone conduction is a technology that transmits sound vibrations directly into your skull bones, from where the vibrations can access the cochlea directly, bypassing the outer and middle ear entirely.
With this in mind, bone conduction can work for the following types of hearing loss:
- Conductive hearing loss. If only your eardrum or the three bones are damaged, bone conduction should work perfectly because it bypasses these organs, communicating sounds directly to the cochlea or inner ear.
- Some cases of mixed hearing loss, mainly if the cochlea still functions.
- Single-sided hearing loss. If you have sensorineural hearing loss, but it’s limited to one ear only, bone conduction devices can transmit sounds from that side to the cochlea of the other ear so that you miss none of the sounds.
In summary, bone conduction is an excellent option for deaf people with conductive hearing loss. However, its benefits are limited in sensorineural or mixed hearing loss cases.
Bone Conduction In The Medical Field
Even though bone conduction headphones for entertainment purposes are still relatively new to the market, the medical field has been using bone conduction devices for decades. It emerged as far back as the renaissance when Girolamo Cardano used a pole between deaf people’s teeth to allow them to hear.
In the 1980s, the first bone-anchored hearing aids (BAHA) became commercially available. These devices are either implanted into the skulls of deaf people or attached in another less permanent way, where they pick up sounds and transmit them directly into the cochlea using bone conduction.
Do Bone Conduction Headphones Work For Deaf People?
Bone conduction headphones are based on the same technology as bone-anchored hearing aids, with only a few differences.
- Bone conduction headphones are not implanted into the skull like BAHA devices. Instead, they rest against your head and transmit the sound vibrations that way.
- While the BAHA is usually implanted into the bone behind the ear (except in children), most bone conduction headphones interact with the bones in front of your ears, like the cheekbones. This doesn’t make much difference, if any, as it has the same result.
So, similarly to the BAHA, deaf people can use bone conduction headphones effectively if they don’t have sensorineural hearing loss.
For example, Some users mention that they have partial deafness in one ear due to a hole in their right eardrum. When these users listen to music through bone conduction headphones, they can hear the sound clearly in their right ear.
In fact, they state that they can hear the music more clearly through the partially deaf right ear than the healthy left ear. It’s interesting because this is a side-effect of bone conduction: it works better when external noise cannot be heard. That’s why people seeking better audio quality from bone conduction headphones also tend to wear earplugs.
Conclusion
Bone conduction works for certain types of deafness. If the person suffers from inner-ear damage, bone conduction is unlikely to work, but for problems with the middle or outer ear, it should enable them to hear, at least to some extent. The medical industry has used bone conduction for decades, and deaf people can now use it commercially for entertainment.
