Hear the Future this World Hearing Day: The history and future of hearing through bone conduction

Dr. Anders Tjellström

Dr. Anders Tjellström

March 3 is World Hearing Day, observed globally and designated by the World Health Organisation. To mark the occasion, The Baha Blog has asked Dr. Anders Tjellström, the pioneering bone conduction surgeon, to reflect on the history of bone conduction and what developments the future could bring to the treatment.


By Anders Tjellström, M.D., Ph.D., D.Sc.hc

It is an old saying that to be able to look into the future you must know the past.

Hearing loss is the most common disability in the industrialised world. The World Health Organisation has estimated that more than 5% of the world population have hearing impairment, and that 1.1 billion teenagers and young adults are at risk of developing hearing loss due to high noise exposure. Around 50% of people between ages 12 and 35 are exposed to excessive noise due to different types of audio devices. How do we handle this situation? The key word is “prevention.”

However, when a patient has already developed hearing loss from noise exposure, hearing devices are often the only solution. In severe cases a surgical procedure placing a cochlear implant in the inner ear might be indicated. Even if sensorineural hearing loss is the most common cause of poor hearing, there is another group of patients who have severe conductive hearing loss. Some patients with congenital malformation and chronic ear disease could be helped with surgery, but for many this is not an option. Some of these individuals cannot use a conventional air conduction hearing aid where the amplified sound is presented through a mould in the external ear canal opening. For these patients, a bone conduction device could be of great benefit.

Direct bone conduction is based on the concept of osseointegration – the process by which bone bonds directly to the surface of an implant – a term introduced by professor Per-Ingvar Brånemark in Sweden. Bone conduction treatment for hearing loss starts with an implant made of titanium placed in the bone behind the ear, onto which a transducer could be attached. The sound goes directly to the inner ear bypassing any defect in the external ear canal and the middle ear. This is called direct bone conduction, and the treatment is indicated in patients with mixed or conductive hearing loss, or single-sided sensorineural deafness (SSD).

In 1977, the first patients were treated with bone conduction at Sahlgrenska University Hospital in Gothenburg, Sweden. This is now a routine operation all over the world, and it has been estimated that about 150,000 to 200,000 hearing impaired people have since been treated with bone conduction.

The hearing instrument and the surgical technique have of course been refined over the years. Engineers have applied modern technology to the early prototype of the 1970s, and today the sound processor is a highly sophisticated device.

Hearing technology has come a long way since the ’70s. The most recent Cochlear Baha 5 Sound Processor is the smallest bone conductor available and comes filled with many programming options that could be controlled wirelessly with the Baha 5 Smart App. It can be adjusted to fit a variety of listening situations with options like audio streaming and Bluetooth connectivity. The Cochlear Wireless Phone Clip allows hands-free use of your phone. Directional microphones make it possible to hold a conversation even in noisy places. Many of the wireless needs we encounter in everyday situations are already available in the Baha portfolio.

The Baha Attract System from Cochlear, where the sound processor is kept in place with a magnet without skin penetration, is already used by many patients. The SoundArc is also a recent addition to the Baha family. No surgery is needed as the high quality and power of the Baha 5 sound processors can overcome most of the soft tissue sound attenuation.

Cochlear is already making strides into the future with hearing technology, but where is bone conduction hearing headed? More and more of the electronic components of the sound processor have already been miniaturised and, looking to the future, could be placed in the implantable part. This means that eventually, the need of skin penetrating coupling might even become obsolete for direct bone conduction.

As bone conduction treatment evolves, more and more people will have access to helpful hearing solutions in the future. It is of course impossible to predict the future of bone conduction, but advances in the last 40 years can give us a clue to how advanced hearing technology could become just 40 years from now.


Anders Tjellström is an ENT-surgeon who performed the first surgery for direct bone conduction hearing in 1977 in Gothenburg, Sweden. He has published and presented bone conduction research at scientific conferences and surgical workshops in more than 50 countries. Tjellström remains active in the field of direct bone conduction as Professor Emeritus at the University of Gothenburg.

 

 

 

 

What You Need to Know: 10 FAQs on the Bone Conduction Procedure

Have you tried the Baha® 5 sound processor on a Baha Softband and decided to move on with a bone conduction implant? Has your child been scheduled for the implant procedure and you need to know how to prepare?

Jennifer Brown, Clinical Product Manager at Cochlear and audiologist, answers the ten most frequently asked questions about the bone conduction procedure.

Jennifer has more than six years of clinical experience in the United States with both pediatric and adult cochlear implant recipients, and she has worked for Cochlear in a variety of roles for the past four years.

(Picture: an audiologist fits a Baha Softband on a toddler’s head. A Baha 5 sound processor is attached to the Softband)

FAQ

1. How do I prepare for the implant procedure?

The good news is that no special preparations are needed before the procedure. The procedure is fast and minimally invasive. Your physician will give you all the details to plan for a successful procedure.

2. Will the procedure be painful?

The procedure is performed under anesthesia. The type of anaesthesia – local or general – is determined by a number of factors, like age, or pre-existing conditions. Ultimately, which anesthesia is right for you is determined by you and your surgeon. Post-operatively, you may experience swelling or skin sensitivity at the implant site. Should it be necessary, your doctor can prescribe pain reliever. Always discuss the procedure and any concerns you may have with your surgeon.

3. Will I be able to go home from the hospital the same day?

In the vast  majority of cases, patients go home the same day. While rare, sometimes in the case of small children or individuals with multiple involvements, the physician may take a precaution and keep the patient over night, but this seldom happens.

4. Can I shower after the procedure?

Usually, patients are allowed to shower the day after procedure. Avoid rubbing the area when drying as this may knock off the healing cap. Cover the cap area by holding a dry towel over it. Here’s what Dr. Pete Weber said in an earlier post.

“The site will still get wet. Since the incision is now very small for Baha Connect surgery, getting the site wet is usually not an issue. Full shower when cap and packing off. The best shampoos to use are the hypoallergenic ones, such as baby shampoos. I also let my Baha Attract patients shower the next day after removing the dressing. Again telling them to pat dry the area and not rub.”

5. If I choose an abutment or a magnet system, how long after surgery until I can wear the sound processor?

Different countries have different regulations.

  • If you choose the abutment system – Baha Connect: depending on where you live it can be anywhere from two weeks to three months before receiving the sound processor.
  • If you choose the magnet system – Baha Attract: depending on where you live it can be anywhere from two weeks to five weeks before receiving the sound processor.

Your doctor will examine the implant site before fitting the sound processor.

6. Are post-operative skin infections common and how are they treated?

As discussed in question 2, there could be swelling or sensitivity at the implant site after the procedure. Post-operative skin infections might occur, although the probability is low. Most skin-related issues happen in the abutment system, because it is skin protruding. In most cases, issues are mild, and can be resolved medically after consultation with your physician. Usually, the skin issues do not affect your ability to wear the sound processor. In the rare incident of persistent skin issues, it may be beneficial to transition to the magnet system.

7. How do I know if an abutment system or a magnet system is appropriate for me?

Both of the Cochlear Baha systems are indicated for individuals with hearing loss in one ear (single-sided deafness, or SSD), or for individuals with conductive/mixed hearing loss.  Whether to choose a Baha Connect or a Baha Attract depends upon a variety of factors, including the degree of hearing loss.

The magnetic system – Baha Attract – is a transcutaneous, or an under-the-skin implant system.  It is comprised of the internal fixture, with a magnet attached to it.  Individuals with the hearing losses noted above are candidates for this system, but it is important to remember that because the sound must pass through the skin, it may be necessary to use a more powerful sound processor, like the Baha 5 Power or the Baha 5 SuperPower.

The abutment system – Baha Connect – is a percutaneous, or through-the-skin implant system.  It too, uses the internal fixture but has an abutment attached to it.  It is appropriate for individuals with SSD or conductive/mixed hearing loss, but unlike the Baha Attract system, there is no skin attenuation of the sound.   This is a great option for individuals needing more power.

In some instances, it may be possible or necessary to transition from one system to another.  For instance, if a recipient chooses the Baha Attract system, and notices a change in his/her hearing, it is possible to remove the magnet and attach an abutment to eliminate dampening of the sound through the skin and to offer more direct bone conduction. Conversely, if a recipient needs to transition to a completely under-the-skin system because of lifestyle or soft tissue concerns, the abutment can be removed and the magnet can be attached.  In both instances, the recipient can likely continue to use the same sound processor.  Cochlear is the only manufacturer that allows for this flexibility based on the patient’s needs.

8. Why do I have to wait so long before I get fitted with a sound processor?

Bone bonds well to titanium, which is what the internal fixture is comprised of. To allow for osseointegration, it is recommended that appropriate healing time be allotted. In an abutment system, the surrounding skin also needs time to adhere to the abutment, to minimize skin issues. In a magnet system, it is important to wait the allotted time to give a chance for the swelling to reduce so that the patient can wear the weakest external magnet possible and still have adequate retention.

9. Will my child need a new implant as she or he grows?

No, an implant is designed for life. There are no pediatric-specific implants, abutments, or magnets. In the event that the child’s hearing changes, non-surgical options – such as a more powerful sound processor – should be tried first. Only in the event of a transition would a procedure be required, but keep in mind the same internal implant is used.

10. Will the Baha® System affect my child’s choices in sports or other activities?

A bone conduction implant is designed to allow your child a world of sound in every activity. While hearing loss is the most important factor to consider when choosing an abutment or a magnet system, lifestyle plays an important role. Some sports may be more conducive to having an under-the-skin magnet system.  It is important to choose a manufacturer that offers your child choices in hearing solutions – whether an abutment, or a magnet.

Remember, communication is key. Always discuss your options and thoughts with your audiologist and surgeon. Your hearing professional will be able to provide timely, accurate, and documented information.

“The Baha 5 Sound Processor has given me back my life, my true passion”

Shelly Shannon is a first grade teacher from Tampa, Florida. She is passionate about her work and the teacher-student exchange.

“I remember the day I woke up and I couldn’t hear. It took my life away”, says Shelly, worried she’d never be in the classroom again. She recounts the difficulties of working as a teacher affected by hearing loss and the exhaustion she’d experience after a day struggling to hear her students.

As soon as she received her Baha 5 Sound Processor, Shelly’s life came back to normal. The sounds she experiences are clear and crisp, regardless of the situation.

“We sit on the porch, listen to the birds sing, and even through the sound of the rain in the background, I can still have a wonderful conversation with my husband”, Shelly says.

With the Baha 5’s Made for iPhone technology, Shelly can easily stream music, TV shows, and video calls directly to her sound processor. Other features include the True Wireless technology, which, according to Shelly makes hearing even better. The TV streamer, the Phone Clip and the Mini Microphone simplify the experience of sound with no strings attached.

How can I wear the Baha 5 SuperPower so I won’t get feedback?

QuestionI upgraded my Baha device to a Baha 5 SuperPower and am, for the most part, happy with the results. However, I am having feedback issues due to the close distance of the abutment to the sound processor. Do you ever recommend moving the abutment? // Rock

Answer: Dear Rock,

In some cases, people who upgrade to the Baha 5 SuperPower may find there is limited space between the abutment and the ear which could increase the risk for feedback. With this in mind, Cochlear created a flexible wearing system that allows you to wear the sound processor under the ear. We have developed a special ear hook to support this and have so far noted good results with this option.

Instead of moving the abutment, I recommend that you contact your hearing care professional to evaluate if wearing your sound processor under the ear instead of behind the ear could be a way to overcome the feedback.

~ Fredrik Breitholtz, Head of Training and Clinical Communication, Cochlear Bone Anchored Solutions

Skylar lost her hearing in a car accident – now she can hear again with the Baha Attract System

Skylar-Baha-Attract-hearing-loss

A terrible car accident left 17-year old Skylar deaf and blind. Now – two years later, her vision is back on one eye and she can hear again thanks to the Baha Attract System.

“In July 2014, my dad and I were driving to church for youth group. Just as we entered an intersection, a driver in a raised pickup truck ran a red light, T-boning and plowing through our small Volkswagen Beetle […] The result was gruesome: My dad was killed instantly and I was airlifted to the hospital in critical condition.”

When Skylar woke up from her medically induced coma, it was to a traumatic brain injury and broken bones in her head, face, and the upper left side of her body. The left side of her face was completely paralyzed, she had profound hearing loss in both ears and was totally blind in her left eye.

After nine surgeries the doctors managed to save her shattered skull and repair her severed facial nerve. The hearing in her right ear came back unexpectedly after two weeks, but she was still completely deaf on her left side.

“I just kind of accepted the hearing loss and went about my life, trying to heal from all the other injuries. Until I had a follow-up appointment with my audiologist a few months later, when she told me I potentially qualified for a Baha device.

I had heard of Cochlear implants, but never bone-anchored hearing conduction devices. The technology was fascinating to me, and I was so excited that I could possibly regain some sound that we scheduled the Baha Attract surgery that very afternoon, for an operation two weeks later.”

Skylar was one of the Anders Tjellström scholarship winners this year, and is currently working as a summer intern in the US, supporting the Cochlear Recipient Services team. She says that she is glad she took the decision to get a Baha implant and that it has definitely changed her life for the better. She loves the magnet, too.

“The cool thing about the Baha Attract is that once the site healed from surgery, there was no more maintenance required. When I take off my processor there’s no sign that I have anything there, and the magnet isn’t strong enough to cause problems when I walk past lockers or fridges. (That was one of my actual concerns going into the procedure!)”

 

Read Skylar’s whole story here

Video: How the Baha Connect System works

The Baha Connect System is a well-proven bone conduction hearing system. It features Cochlear’s unique minimally invasive DermaLock technology which helps preserves the hair and skin around the abutment, thus improving the aesthetics after surgery. Watch how it works in the video above.

baha-5-blond-sound-processorWatch how fitness instructor Carole’s Baha 5 Sound Processor stays on during her spinning class here.

Read more about the Baha Connect System

Video: How the Baha Attract System works

The Baha Attract System is a comfortable and easy to use hearing system that requires no daily skin care. The sound processor is easy to handle, and snaps onto an external magnet to hold it in place, as seen in the video above.

Baha-5-magnet-hearing-aidJon and his wife noticed a great difference in his hearing after he got his Baha Attract System. Watch his story here.