Is a Bone Anchored Hearing System Right for Me?
Is a Bone Anchored Hearing System Right for Me?
Hearing is a big part of our lives; it is what connects us to the world. But sometimes we need help with our hearing.
Amplification, better known as hearing aids, is the most common treatment option for hearing loss. Most people are familiar with what a hearing aid is but there are other hearing solutions such as a cochlear implant or a bone anchored system that are less well-known. While standard hearing aids are suitable for most individuals suffering with a hearing loss, cochlear implants and bone anchored hearing systems are for individuals who meet specific candidacy criteria. This article focuses on the specific criteria for individuals considering a bone-anchored system. For more information on cochlear implants click here.
Conductive Hearing Loss
Individuals with conductive hearing loss (sound blocked from reaching the inner ear) are ideal candidates for a BAHS. Conductive losses can be minor, for example, when you are sick with a cold and feel like you can’t hear as well. Here, fluid or congestion in the middle ear space attenuates (blocks) some of the sound from getting through. Or, conductive losses can be maximal. For an individual born without an outer ear/ear canal (known as microtia/atresia). sound cannot travel naturally through the air to the inner ear. This would be considered a maximal conductive hearing loss.
However, not every individual with a conductive hearing loss is a clear candidate for a BAHS. There needs to be a big enough difference, usually around 30dB, between the air conduction thresholds and the bone conduction thresholds to indicate that a BAHS is suitable. This is known as the air-bone-gap (ABG). A study was conducted to determine the ideal ABG in which a BAHS provides significant improvement over a standard hearing aid. The results indicated that a 30dB ABG would be a good rule of thumb for determining candidacy.
More specifically, the ABG is the difference between sound that is heard when it passes through the air (earphones in the ears) versus when it passes through the bone (a vibrating earpiece behind the ear). An individual’s thresholds (smallest sound that they can hear) may vary depending on the transmission pathway (air vs. bone), and when they differ enough, it indicates a conductive component to the individual’s hearing loss.
People with mixed hearing loss are also good candidates, especially if they have an ABG of at least 30 dB as mentioned above. Mixed hearing loss refers to cases in which individuals have an underlying sensorineural hearing loss (problem with inner ear hearing organ) as well as a conductive component (blockage/problem with outer or middle ear). In these cases, the sound signal picked up by the processor is analyzed and amplified based on the individual’s underlying sensorineural hearing loss before it is converted into vibrations to be transmitted across the skull to the inner ear organs. In these cases, the signal reaching the inner ear will be appropriately compensating for the underlying hearing loss. Bone anchored systems are able to overcome both the conductive and the sensorineural component of a mixed loss.
For some individuals, only one ear is functional. This is what is known as Single Sided Deafness (SSD) and this makes it very difficult to communicate in noise and to determine where sounds in the environment are coming from. Listening with one ear requires more effort than when we have access to sounds from both our ears. Some people with SSD struggle with their hearing difficulties in everyday life while others seem to manage okay.
A bone-anchored system is a treatment option for individuals with SSD in that it will provide a sense of sound awareness from their “deaf” side. It does not bring hearing back to the “deaf” ear but instead allows the sound arriving at that ear to be transmitted (through bone conduction) to the better hearing ear. It is still the functioning ear that hears the sound.
A BAHS for individuals with SSD can be very useful, especially with children. It can provide better hearing abilities in noise (i.e. classrooms), decreased listening effort and sound awareness in all directions – very important for safety reasons!
Other – Contraindications to Conventional Hearing Aids
Most people with hearing loss wear a standard or conventional hearing aid. These devices consist of a one or two microphones, an amplifier and a receiver or speaker. Sounds are picked up by the microphones, analyzed and amplified according to the individual’s hearing loss and sent through the receiver into the ear canal. There are a variety of different styles of hearing aid available (behind the ear, in the ear, etc.). Regardless of the type of hearing aid a user chooses there will always be component that sits directly in the ear canal. For most individuals this isn’t a big issue, but for those who have chronic ear infections that cause a lot of fluid drainage from the ear, or individuals who have certain skin conditions, wearing a conventional hearing aid with something sitting in their ear canal may not be appropriate or effective. BAHS to the rescue! Since these devices are mounted to the head either by a headband or onto an implanted abutment, it sits directly behind the ear, leaving the ear canal wide open.
Ask Your Health Care Provider
If you fit into one of these categories, then a BAHS may be a good solution for you. Talk to your health care provider (doctor, audiologist, or ENT) today! They will be able to advise you on this solution and guide you through the process.