Traditional hearing aids consist of a microphone, amplifier and speaker. The microphone is positioned on the outside of the ear and receives sound waves that are then transported to the amplifier, which strengthens the sounds being received before they are processed through a speaker. The speaker is located in the middle or inner ear and allows the wearer to hear sounds in a louder or clearer frequency than they would be able to without the hearing aid.
Bone-anchored hearing aids work rather differently than traditional hearing aids and can help restore hearing in those who are not suitable candidates for traditional hearing aids, such as those with middle ear malformations or unilateral hearing loss. Here's an overview of how bone-anchored hearing aids work and how they are fitted:
How Bone-Anchored Hearing Aids Work
Bone-anchored hearing aids are surgically implanted and do not rely on the process of amplifying sounds in the ear canal in the way that traditional hearing aids do. Instead, they utilise vibrational bone conduction of sound from an implanted device on the skull to the inner ear, which allows the outer and middle ear to be bypassed altogether. This makes them a great option for those with conductive hearing loss, which refers to hearing loss caused by problems with the outer or middle ear.
Bone-anchored hearing aids consist of an external sound processor and a titanium implant that's attached to the skull. The sound processor has a highly sensitive microphone that picks up sounds and transports these sounds in the form of vibrations to the titanium implant. The implant then transfers these vibrations to the skull and the sound waves travel down to the inner ear. Within the inner ear, the sound waves are picked up by the auditory nerve and sent to the brain to be processed into the final sounds that will be experienced.
The Surgical Procedure Explained
Situating a bone-anchored hearing aid is typically carried out as a day case procedure using a local anaesthetic to numb the area of bone just behind the ear where the titanium implant will be fitted. The implant is only a few millimetres in diameter and your surgeon will make a small incision into the bone and secure the implant in place. The implant will protrude slightly to allow the sound processor to be attached to it, and the sound processor has a built-in magnet to make it easy to attach. The sound processor won't be attached until the implant incision has healed, which can take a few weeks, and before it's attached, it will be programmed to get the best results based on your previous hearing tests and degree of hearing loss.
Bone-anchored hearing aids are discreet and user-friendly. If your doctor suggests they could be a suitable option for you, ask to see the different models that are available to get an idea of how they would look on you, and ensure you get the opportunity to ask any questions you have before scheduling the procedure.
If you have additional questions about hearing aids, contact a local audiologist.