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HiResolution Bionic Ear Cochlear Implant System -- with the AURIA BTE
Bilateral Cochlear Implants go Mainstream
Loren J Bartels, MD, FACS
Christopher J Danner, MD
Tampa Bay Hearing and Balance Center
Tampa Bay Hearing and Balance Center
For more than 25 years, cochlear implants have revolutionized the world for deaf and severely hearing impaired persons. Many comment on how their lives are better with improved ability to hear and communicate orally in quiet, direct conversational situations. One elderly lady, with a large mischievous smile and family around her, has repeatedly said to the embarrassment of her surgeon, "You're the best thing that has ever happened to me." She explained that cochlear implant hearing gave her back to her family and them back to her. Another garrulous woman with a cochlear implant, standing at the doctor's checkout desk, said to another cochlear implant person, "I'm a hearing person who just happens to be deaf. My cochlear implant gave me my life back." And, a young boy, a promising baseball player, brought his surgeon a grand slam homerun ball that won the last game of his season as a thank-you for "giving me an ear that is a lot better than my old ones."
Many cochlear implant recipients are happy with hearing from just one ear, but even good-hearing cochlear implant recipients commonly have difficulty hearing in noise. Even in mildly noisy situations, a single cochlear implant does not seem loud or clear enough, in part because two ears are needed to provide direction of sound, focus on a speaker, and suppress extraneous sounds. A growing body of research now shows that many of these deaf individuals benefit from bilateral (two ear) hearing restoration with cochlear implants. Fascinating is that the same physiological tools normal hearing folks use to hear better in noise with two ears (binaural hearing) also help bilateral cochlear implant individuals.
With sounds occurring all around us, it is important to have access to sounds from both sides. If only one ear is implanted, sounds originating from the other side are not perceived as loudly or as clearly. In group listening situations, the person with a single cochlear implant often needs to place the implanted ear toward the more desirable sound source. This occurs at the expense of the sounds from the other side. Consider the implications for a child in a classroom or playground situation, or the adult at a business meeting or in a restaurant.
Sound localization skills are improved in most persons who receive bilateral cochlear implants. Locating the speaker allows not only more direct access to lipreading, but it also improves the ability to utilize other benefits of binaural hearing. When the listener locates and faces the speaker, sound from the speaker reaches the listener's ears and, secondarily, the brainstem simultaneously. Within the brainstem is the first level of auditory processing efforts: sound that reaches both ears simultaneously summates meaning the brain adds information from each ear to make the speech seem both a bit louder and noticeably clearer. Sound that reaches the brainstem from each ear can be non-simultaneous too, meaning different sounds are perceived at different times even though the sound may be occurring together in the environment. For example, speech from a person speaking from one side reaches one ear before it reaches the other. The brainstem actually suppresses noise that reaches the brainstem in a non-simultaneous manner, a concept called squelch. This allows the brain to reduce sounds selectively, as if side-noise is less important than the speech that comes to each ear simultaneously. The result of these two benefits in binaural hearing, including listening with cochlear implants, is improved speech recognition in noise. A baby implanted binaurally at one year of age began to find her noisy older brothers so well within months after surgery, that she spontaneously began to imitate them. Now age three, she holds conversations in a normal manner, picking to whom to listen from among her many adult and peer admirers, delighting us all.
One other feature of binaural hearing is the head shadow affect. In this concept, sounds that reach one ear directly from the side in a somewhat noisy situation will not be heard nearly as well in the opposite ear. The ear opposite the sound is in a sound shadow created by the head. In that way, the head serves as a buffer to noises coming from the other side of the head, making speech easier to understand. If the unwanted sound from the side is coming directly to the poorer hearing (e.g., non-implanted) ear, it is then relatively easy to ignore, while the better ear that is in the head shadow concentrates on sounds from directly in front. However, in cases of a single cochlear implant, if the unwanted sound is directed to the ear with the implant, then the individual is unable to take advantage of the head shadow. But, if both ears hear equally, both normal ears and the bilateral cochlear implant condition can often facilitate this kind of listening because the brain can more readily ignore the sound from one side if the ear in the head shadow hears well. In a noisy doctor's waiting room, a 10-year-old girl implanted soon after meningitis deafened both ears was observed talking on the phone with one ear alternating listening to a friend with the other ear. She was literally able to choose on which ear to concentrate because with her bilateral cochlear implants; she had quite usable hearing in both ears.
When the deafness is relatively symmetric in development and severity, good reason exists to believe that bilateral cochlear implants would be the best possible rehabilitation. Other unique situations exist where a second ear cochlear implant may be considered, for example, if the first ear does not do well, or the CI user has the desire for further enhanced performance.
Situations do exist where we might not recommend bilateral cochlear implants. A person completely deaf for more than 20 years in one ear and only recently deaf in the second ear is less likely to benefit from implanting the long deaf ear, but some do. Sometimes, an ear thought to be "deaf" for many years, has in fact been severely impaired rather than deaf. These ears may be a candidate for a second cochlear implant. Reviewing historical audiometric hearing data is important in separating out this critical difference.
The medical and anatomical condition of each ear is also an important factor to consider when assessing candidacy for bilateral cochlear implantation because physical conditions may exist that render one ear a poor candidate for an implant. For example, we likely would not recommend bilateral cochlear implants for a person who had severe reactive bone (often called ossification) filling one inner ear but not the other after meningitis, making cochlear implant surgery in that ear less likely to be effective. For a person with a severely deformed inner ear on one side and a more normal one on the other, a single implant may be more appropriate.
Exciting recent research shows improved ability to hear in noise when newer computerized cochlear implant strategies stimulate both ears simultaneously. Using moderately higher stimulation rates, such as is available with HiResolution Sound Processing across 16 channels, some bilateral cochlear implant patients had dramatically better ability to hear in noise.1 The first-implanted ear is likely to remain the preferred ear, but good benefit from implanting the second ear does develop over time.2 Many children with cochlear implants reach a point in school where listening in the classroom is quite tiring, which can affect learning. This problem may be lessened by providing the second cochlear implant.3 Click here for recently published research articles that clearly demonstrate the benefit of bilateral cochlear implantation.
Note that the FDA approval for cochlear implants does not restrict their use to a unilateral surgery. Neither does Medicare restrict cochlear implants to a unilateral surgery. With both the benefit and regulatory information available, the consensus among cochlear implant centers now is that bilateral cochlear implants are preferable in some patients. Note that simultaneous bilateral cochlear implants (implanting both ears at the same time) are less expensive than sequential implantation (implanting the second ear later). Many health insurance companies, after reviewing the potential benefits, do approve bilateral cochlear implants. For those situations in which the insurer is reluctant or an internal reviewer doubts the potential benefit of bilateral cochlear implants, the articles below can be helpful. As well, the Let Them Hear Foundation Advocacy Program happily helps with appeals if a denial has been received for cochlear implant coverage. See them at Let Them Hear Foundation :: Advocacy.
With bilateral cochlear implants becoming more mainstream, an additional question now needs to be considered for newcomers to this technology-one implant or two? More and more individuals that already have one cochlear implant are now considering "going bilateral." If you are thinking about bilateral cochlear implants, have a frank discussion with your cochlear implant team to evaluate the potential benefits and feasibility for you or your child
Bilateral Cochlear Implants go Mainstream
Loren J Bartels, MD, FACS
Christopher J Danner, MD
Tampa Bay Hearing and Balance Center
Tampa Bay Hearing and Balance Center
For more than 25 years, cochlear implants have revolutionized the world for deaf and severely hearing impaired persons. Many comment on how their lives are better with improved ability to hear and communicate orally in quiet, direct conversational situations. One elderly lady, with a large mischievous smile and family around her, has repeatedly said to the embarrassment of her surgeon, "You're the best thing that has ever happened to me." She explained that cochlear implant hearing gave her back to her family and them back to her. Another garrulous woman with a cochlear implant, standing at the doctor's checkout desk, said to another cochlear implant person, "I'm a hearing person who just happens to be deaf. My cochlear implant gave me my life back." And, a young boy, a promising baseball player, brought his surgeon a grand slam homerun ball that won the last game of his season as a thank-you for "giving me an ear that is a lot better than my old ones."
Many cochlear implant recipients are happy with hearing from just one ear, but even good-hearing cochlear implant recipients commonly have difficulty hearing in noise. Even in mildly noisy situations, a single cochlear implant does not seem loud or clear enough, in part because two ears are needed to provide direction of sound, focus on a speaker, and suppress extraneous sounds. A growing body of research now shows that many of these deaf individuals benefit from bilateral (two ear) hearing restoration with cochlear implants. Fascinating is that the same physiological tools normal hearing folks use to hear better in noise with two ears (binaural hearing) also help bilateral cochlear implant individuals.
With sounds occurring all around us, it is important to have access to sounds from both sides. If only one ear is implanted, sounds originating from the other side are not perceived as loudly or as clearly. In group listening situations, the person with a single cochlear implant often needs to place the implanted ear toward the more desirable sound source. This occurs at the expense of the sounds from the other side. Consider the implications for a child in a classroom or playground situation, or the adult at a business meeting or in a restaurant.
Sound localization skills are improved in most persons who receive bilateral cochlear implants. Locating the speaker allows not only more direct access to lipreading, but it also improves the ability to utilize other benefits of binaural hearing. When the listener locates and faces the speaker, sound from the speaker reaches the listener's ears and, secondarily, the brainstem simultaneously. Within the brainstem is the first level of auditory processing efforts: sound that reaches both ears simultaneously summates meaning the brain adds information from each ear to make the speech seem both a bit louder and noticeably clearer. Sound that reaches the brainstem from each ear can be non-simultaneous too, meaning different sounds are perceived at different times even though the sound may be occurring together in the environment. For example, speech from a person speaking from one side reaches one ear before it reaches the other. The brainstem actually suppresses noise that reaches the brainstem in a non-simultaneous manner, a concept called squelch. This allows the brain to reduce sounds selectively, as if side-noise is less important than the speech that comes to each ear simultaneously. The result of these two benefits in binaural hearing, including listening with cochlear implants, is improved speech recognition in noise. A baby implanted binaurally at one year of age began to find her noisy older brothers so well within months after surgery, that she spontaneously began to imitate them. Now age three, she holds conversations in a normal manner, picking to whom to listen from among her many adult and peer admirers, delighting us all.
One other feature of binaural hearing is the head shadow affect. In this concept, sounds that reach one ear directly from the side in a somewhat noisy situation will not be heard nearly as well in the opposite ear. The ear opposite the sound is in a sound shadow created by the head. In that way, the head serves as a buffer to noises coming from the other side of the head, making speech easier to understand. If the unwanted sound from the side is coming directly to the poorer hearing (e.g., non-implanted) ear, it is then relatively easy to ignore, while the better ear that is in the head shadow concentrates on sounds from directly in front. However, in cases of a single cochlear implant, if the unwanted sound is directed to the ear with the implant, then the individual is unable to take advantage of the head shadow. But, if both ears hear equally, both normal ears and the bilateral cochlear implant condition can often facilitate this kind of listening because the brain can more readily ignore the sound from one side if the ear in the head shadow hears well. In a noisy doctor's waiting room, a 10-year-old girl implanted soon after meningitis deafened both ears was observed talking on the phone with one ear alternating listening to a friend with the other ear. She was literally able to choose on which ear to concentrate because with her bilateral cochlear implants; she had quite usable hearing in both ears.
When the deafness is relatively symmetric in development and severity, good reason exists to believe that bilateral cochlear implants would be the best possible rehabilitation. Other unique situations exist where a second ear cochlear implant may be considered, for example, if the first ear does not do well, or the CI user has the desire for further enhanced performance.
Situations do exist where we might not recommend bilateral cochlear implants. A person completely deaf for more than 20 years in one ear and only recently deaf in the second ear is less likely to benefit from implanting the long deaf ear, but some do. Sometimes, an ear thought to be "deaf" for many years, has in fact been severely impaired rather than deaf. These ears may be a candidate for a second cochlear implant. Reviewing historical audiometric hearing data is important in separating out this critical difference.
The medical and anatomical condition of each ear is also an important factor to consider when assessing candidacy for bilateral cochlear implantation because physical conditions may exist that render one ear a poor candidate for an implant. For example, we likely would not recommend bilateral cochlear implants for a person who had severe reactive bone (often called ossification) filling one inner ear but not the other after meningitis, making cochlear implant surgery in that ear less likely to be effective. For a person with a severely deformed inner ear on one side and a more normal one on the other, a single implant may be more appropriate.
Exciting recent research shows improved ability to hear in noise when newer computerized cochlear implant strategies stimulate both ears simultaneously. Using moderately higher stimulation rates, such as is available with HiResolution Sound Processing across 16 channels, some bilateral cochlear implant patients had dramatically better ability to hear in noise.1 The first-implanted ear is likely to remain the preferred ear, but good benefit from implanting the second ear does develop over time.2 Many children with cochlear implants reach a point in school where listening in the classroom is quite tiring, which can affect learning. This problem may be lessened by providing the second cochlear implant.3 Click here for recently published research articles that clearly demonstrate the benefit of bilateral cochlear implantation.
Note that the FDA approval for cochlear implants does not restrict their use to a unilateral surgery. Neither does Medicare restrict cochlear implants to a unilateral surgery. With both the benefit and regulatory information available, the consensus among cochlear implant centers now is that bilateral cochlear implants are preferable in some patients. Note that simultaneous bilateral cochlear implants (implanting both ears at the same time) are less expensive than sequential implantation (implanting the second ear later). Many health insurance companies, after reviewing the potential benefits, do approve bilateral cochlear implants. For those situations in which the insurer is reluctant or an internal reviewer doubts the potential benefit of bilateral cochlear implants, the articles below can be helpful. As well, the Let Them Hear Foundation Advocacy Program happily helps with appeals if a denial has been received for cochlear implant coverage. See them at Let Them Hear Foundation :: Advocacy.
With bilateral cochlear implants becoming more mainstream, an additional question now needs to be considered for newcomers to this technology-one implant or two? More and more individuals that already have one cochlear implant are now considering "going bilateral." If you are thinking about bilateral cochlear implants, have a frank discussion with your cochlear implant team to evaluate the potential benefits and feasibility for you or your child
