For a while, bone conduction became popular in earphones.
Bone conduction is also used in hearing aids. Bone conduction in hearing aids is a method in which an implant is surgically implanted in the skull and the hearing aid is placed there, transmitting sound through vibrations from the skull.
Let's take a closer look at this type of implantable hearing aid.
Characteristics of Implantable Hearing Aids
Implantable hearing aids use bone conduction to transmit sound so that the user can hear.
This is a fundamentally different approach than that of ordinary hearing aids, which use air conduction to convert and amplify sound closer to the ear into a sound that is easier for the user to hear. This is why bone conduction can be uncomfortable for some people in the beginning. Unlike other hearing aids, this implant-type hearing aid does not emit sound from the body. Unlike regular hearing aids, which are placed in the ear or hooked to the ear, implant-type hearing aids are surgically implanted with a screw in the skull. This is similar to attaching a dental implant to the head. The main body is attached to this implant with a snap. The implant-type hearing aid is labeled "Baha," which stands for "bone anchored hearing aid.
Surgery to use an implantable hearing aid
Implantable hearing aids require surgery to insert a screw into the skull. Surgery is a big deal, scary, and expensive! It sounds scary and expensive! Baha's surgery is not that extensive.
In other countries, it is often a one-day procedure, and even in Japan, the hospitalization period is relatively short. In addition, both the surgery and the body itself are covered by insurance. However, this does not mean that anyone can undergo Baha surgery.
The following conditions must be met to be eligible for the surgery
- Binaural hearing loss
- Has an obstruction of the external auditory canal, otosclerosis, a pearly seed, or an ossicles deformity that has not improved after surgery
- Hearing in both ears or at least one ear is within 45 dB
- Must be at least 18 years old (15-17 years old with parental consent)
Advantages of Implantable Hearing Aids
So what are the advantages of implantable hearing aids? The following are possible advantages.
- No need to worry about steam because the ear is not blocked
- Bone conduction, so you can hear even if you have problems in the outer or middle ear
The biggest advantage of the implant type is that it directly stimulates the cochlea with vibrations, so even if there is a problem in the outer or middle ear, you can skip it and hear the sound. Therefore, even if there is a problem with the eardrum or other parts of the ear, you can still hear sound clearly.
Disadvantages of the implant type
What are the disadvantages of the implant type? The following are possible disadvantages.
- Cannot be used for people with severe hearing loss and above
- Cannot be used immediately after surgery
- Small children cannot use it
- It directly stimulates the auditory nerve, which may be aggravated if the volume is too loud
As mentioned in the surgical requirements, young children cannot use implantable hearing aids because they must be at least 18 years old to undergo the surgery in the first place.
Another obstacle is that they cannot use it for 3 months after the surgery because they need to wait until the implant is firmly fixed. People with severe hearing loss, such as profound hearing loss, cannot use them either, as they must still have hearing within 45 dB. The more severe the hearing loss, the greater the output of the hearing aid must be, and in the case of bone conduction, the vibration becomes too strong and rattles, making the hearing aid completely unusable.
Who is suited to implantable hearing aids?
Not everyone who is considering a hearing aid is a candidate for an implant-type hearing aid. People with hearing loss due to damage to the outer or middle ear and who are of legal age are usually suitable for implantable hearing aids. Basically, people who use implant-type hearing aids have limited causes and should be aware that not everyone can use this type of hearing aid.
Manufacturers of implantable hearing aids
Not many people have seen these implant-type hearing aids. The only approved implant-type hearing aids in Japan are made by a company called Cochlear.
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