Category Archives: Education

The Future of Hearing Correction

Coming Soon

Coming Soon

It’s interesting to think through the parallels between vision and hearing correction over the years. First you had eye glasses, which could correct the shortcomings in vision, but through an outwardly visible prosthesis you wore over your ears and nose. Over time, the glasses got smaller and the corrective powers grew larger.

Then came contact lenses, which were equally effective, but completely invisible to the outside world. No one need ever know.

Finally came LASIK, which could physically correct the shape of your eye. In a sense you are “fixing your body”.

If you think about it, hearing correction is following a similar progression. First you had hearing aids, the “eye glasses” of the hearing world. They amplify sound and are worn in an external prosthesis that sits over the ear. Over time the aids have gotten smaller and more powerful, with recent models even fitting entirely within the ear!

custom-hearing-aid

In the Ear Hearing Aid

Then came Cochlear Implants, which could actually bypass damaged hearing nerves to provide a wider range of correction. Not directly analogous to eye glasses since they do more then amplify sound, but from an outward perspective they are still bulky and noticeable:

processor on ear

Cochlear Implants of Today

To me there are 2 logical next steps remaining in this progression: first, an entirely “invisible” corrective hearing mechanism, similar to contact lenses. And finally an actual physical “correction” to the body, similar to LASIK.

In terms of the first, research has already been underway on a “completely internal cochlear implant” for some time. As far back as 2000, a company called Epic Biosonics was working on a device that would be

“fully implanted into the middle ear….a microphone is implanted under the skin in the ear canal. This picks up sound and sends it to a speech-processing device which is similarly implanted under the skin behind the ear. “

(Totally Implantable Cochlear Implant History). In other words, an implant that is outwardly completely invisible!

This sounds fantastic until you read down further that “Epic ran into a particularly difficult technical hurdle and had to shelve the development of this exciting implant.” Epic was later acquired by Med-El (first discussed in my post on Big Business), which to my knowledge offers no such device currently.

In 2011 another company called Otologics was attempting the same feat, but then was later acquired by another CI vendor called Cochlear in what looks to be a bargain basement bankruptcy offering. Clearly there are some challenges still remaining with this technology, but the optimist in me feels it is only a matter of time before we figure those out.

Of course the true correction, the “LASIK” of the hearing world is further out still. There are really two aspects to this: better amplification of sound (glasses/contacts/lasik), and providing sound where there was none before (Cochlear Implants). In terms for the former, hearing loss is trailing vision loss, but in terms of the latter, hearing loss seems further ahead.

As little as I know about hearing loss, I know even less about blindness, despite being extremely nearsighted myself. I pray I do not need to become an expert on that topic, but nevertheless remain a constant technology optimist.

Progress marches on…

Big Week Next Week

So after a period of relative quiet, next week is a big week for Fiona. Monday she is having an MRI and Wednesday she will receive her first hearing aids.

MRI

I think most everyone knows what an MRI is: it provides a more detailed picture inside the body then is otherwise possible through X-Rays alone. For example:

Sample MRI Image

Sample MRI Image

Many of us may have even had one, myself included. What I didn’t know, however, was exactly how they work – it’s pretty amazing.

There’s a good article on one of my favorite sites HowStuffWorks about this, but its pretty long and technical. Here’s my vastly oversimplified explanation:

  • The body is made up mostly of water, water contains hydrogen, hydrogen has protons.
  • Magnetic fields from the machine align those protons in the direction of the field. A small number of those protons do not align.
  • Those protons that do not align are hit with a specific radio frequency wave that causes them to absorb energy.
  • When the wave is turned off, those protons emit that energy. That energy is then absorbed by “coils” in the machine that feed data into a computer.
  • The computer runs complex math to map that data into a picture like you see above.

Pretty magical stuff. Go Science!

Here’s a good infographic from the How Stuff Works article:

Steps of an MRI

Steps of an MRI

If you’ve ever seen a MRI machine, its pretty intimidating and claustrophobic:

mri-scanner

Because Fiona is an infant, she will need to be sedated with general anesthesia for the procedure. As a parent, this will doubtless be tough to watch, but is surely better than a baby screaming her head off inside a big scary machine.

From this procedure we are hoping to get our first insight into the cause of her hearing loss, and more importantly her candidacy for Cochlear Implants (see my earlier post about Auditory Brainstem Implants). While it is not guaranteed we will have all the answers on Monday, we do expect to learn more of the puzzle.

Hearing Aids

On Wednesday Fiona gets fitted with her hearing aids. While we are not expecting any significant response from the aids, the audiologist advised us to bring a camcorder “just in case”.

Personally we don’t expect to see a response like we’ve seen from the CI and ABI videos in earlier posts, but it is possible Fiona will hear SOME new sounds for the first time. We’re keeping our expectations in check, but nevertheless I will keep the camera rolling “just in case”.

Stay tuned.

Frequencies of Familiar Sounds

This is a useful diagram that helps explain the hearing retest I posted about last time. It shows the frequencies and volume levels of common sounds such as water dripping, a piano playing, and a bird chirping. It also shows the “speech banana” including common phonemes such as “j”, “ch”, “th” and where they fall (see my earlier post for more information).

Frequency Spectrum of Familiar Sounds

Frequency Spectrum of Familiar Sounds

Note also the ranges of loss on the right hand side: “mild”, “severe”, “profound”, etc.

I highlighted in red the approximate area where Fiona responded in her right ear during the retest.  There were no responses in her left ear.

The funny thing is that in her original test, the results were the exact opposite (left ear instead of right). Unfortunately this discrepancy needs to be resolved to properly program her hearing aids, so the tie-breaker test is coming on Monday.

Anyway, I thought this diagram gave a helpful perspective. I guess Fiona will be enraptured the next time I mow the lawn 🙂

The Second Opinion

Bright and early this morning, Eliza and I made our way out to the Alpharetta location of Northside Pediatric Hospital to perform Fiona’s hearing retest. Different audiologist and different equipment, a qualified second opinion.

Rather then braving a 75 minute rush hour drive, we decided to stay the prior night at Grandma and Grandpa Underwood’s house. A wise choice, as our drive was now only 10 minutes.

Northside Pediatrics - Alpharetta

Northside Pediatrics – Alpharetta

If you recall from my earlier post about the Hearing Test, we had both the Otoacoustic Emission (OAE) Test as well as the Auditory Brainstem Response tests rerun today. This time we were much better prepared for the long stay: bouncy chairs, “boppy pillows”, pacifiers, you name it – we were pimped out.

The test ran about 3 hours, just like last time. For the most part Fiona was cooperative, thanks to the amazing rocking skills of Mom. Fiona had to remain very still, with electrodes on her head measuring the responses received from various sound pulses generated into a small earpiece. You can see her sporting some stylish head gear (with an intriguing “Mona Lisa” Eliza smile) in the pic below:

Auditory Brainstem Response Test

Auditory Brainstem Response Test

Unfortunately our small hopes of a miraculous misdiagnosis from the original test were quickly put to rest, as the results were consistent with profound loss. We didn’t really expect anything different, but you can’t help but have that small hope…

Over the 3 hours, the audiologist patiently ran through all the frequencies in both ears and recorded virtually identical results to before: severe to profound loss in both ears.

She also ran a pulse test through the skull that tests for conductive hearing loss (hearing loss that occurs due to obstructions in the outer ear canal or bones) versus sensorineural hearing loss (hearing loss that occurs due to damage in the inner ear/cochlea). Conductive loss is usually correctable through surgical means. Sensorineural loss is not currently correctable in itself by surgical means, and is instead treated with hearing aids or cochlear Implants. Fiona was confirmed with sensorineural loss, which was as we expected.

One interesting anomaly, though, was they found slight response to low level frequencies in her right ear…the exact opposite result we got last time (left ear). Because of this inconsistency, we unfortunately need to return next week for another retest to confirm consistency. Awesome.

All in all, though, this test ran much smoother since we knew what to expect. More importantly, though, we weren’t in an emotional shock, which allowed us to ask a lot of great questions. Some things I learned:

  • Hearing aids are still beneficial to babies with profound loss, even though they can not hear speech (see Fred Flintstone Teaches Us About Hearing Loss). Why? Because stimulation of the auditory nerve forestalls atrophy and readies the baby for the introduction of a signal from the Cochlear Implant.
  • Reading the chart from the ABR test (see Hearing Test post), we learned the x-axis charts latency of sound received. In other words, the quicker the baby hears a sound, the further to the left you will see a jump in the graph. The audiologist is looking for those jumps to occur within certain periods of time, depending on the volume.
  • Northside has done CI surgery on qualified infants less than 1 year old with great results. (1 year is the current FDA limit). The kicker is not all insurance companies cover prior to 1 year. We’ll need to check on that, but we definitely want asap so we can hit her speech centers early.
  • I asked if babies with the surgery done at 1 year old develop speech indecipherable from hearing children. The audiologist responded with an almost surprised “of course” response, which was extremely comforting. One of her patients even grew up to have a distinct southern accent, not sure how i feel about that :-).

Since we are returning next week for yet another retest, Fiona did not get fitted for hearing aids today, but that will be on the docket next week. (Recall she will first need to wear hearing aids for 3-6 months before candidacy for the CI, which is the path we expect).

While we didn’t receive any miracles today, we also didn’t receive any surprises, and left more informed and confident. I’ll call that a check in the plus column.

The Big Business of Cochlear Implants

There are three major players in the Cochlear Implant business. The first, based in Australia, has the eminently functional, yet very uninspiring name “Cochlear“. The second, based in Austria, has an even bigger yawner name with “Med-El“. I have no idea what the “El” stands for.

But the third…the third is a doosie:  Advanced Bionics. Now how freakin’ cool is that? Lasers, top secret labs, bionic superpowers, I’m expecting it all! And hailing from the good ‘ol USA as well! Proud to be an American!

Of course, like most geeky engineers, I am a product of FAR TOO MUCH science fiction. So with a name like Advanced Bionics, I just can’t resist channeling my inner nerd…

Since we know everything on TV is always true, I figure we’re 20-30 years away from technology running amok and ultimately enslaving the human race. In fact, could Advanced Bionics be the real-world equivalent of Cyberdyne Systems from The Terminator movies? Hmmm, I might be on to something…

AdvancedBiotics

Doomsday jokes aside, its really cool to see competition and innovation occurring in the CI space. This benefits us all. In fact, Advanced Bionics even has an ipad app that allows you to customize the color combinations of your implant! Implants as fashion statements – something I’m sure I will never truly understand, but will no doubt be critical to our little girl as she grows up.

Check out these screenshots to get a flavor of the customization possible. The days of boring old tan colored hearing aids are so “2000-late”.

ab_ipad_config

ab_ipad_step3ab_ipad_step4

I guess it’s true, there really is an “app for that”.

Auditory Brainstem Implants in the News

Quick bonus post this morning:  Auditory Brainstem Implants (ABI) made their way through mainstream news yesterday with the story of 3 year old Grayson Clamp who recently received an ABI in my old ‘hood at UNC Chapel Hill. Check out the CNN Story and here’s a youtube video:

If you recall from my earlier post on ABIs, the brainstem implant is a more invasive procedure then Cochlear Implants (CI), reserved for patients in which the auditory nerve is damaged and the CI is ineffective. What’s particularly newsworthy is that ABIs have historically only been done on adults – Grayson is the first child in the US to receive one.

What’s amazing to me is I just last week talked about a new study for children, and then BAM we already have a positive story. Amazing how fast things move.

Our hope is that the Fiona is eligible for the CI and will not need an ABI. The odds are in her favor, but we won’t know for sure in some time. We do have an MRI scheduled for July 15th, so hope to know more at that time.

Many thanks to everyone who sent me the link to this story, I hadn’t heard of it until you reached out to me.

Fred Flinstsone Teaches Us About Hearing Loss

Here’s a fun 40 second video Eliza found – it shows an example of what a typical life activity, in this case watching the Flintstones, would sound like to individuals with different levels of hearing loss (mild-moderate-severe).

Yabadabadoo!

Yabadabadoo!

The blue shape in the graph is called the “speech banana” (no joke) and represents the region on an audiogram where the sounds of speech typically fall. The x-axis left-to-right represents increasing frequency heard (think bass to treble) while the y-axis represents an increasing volume (dB) threshold needed to hear that frequency. The red line shows the actual threshold limits for individuals with the various levels of loss throughout the video.

As the video progresses, watch as the right side of the red line dips further down. Once it dips below the blue “banana” you can instantly hear the speech getting muffled. The further it dips, the worse the effect. It is more typical to have loss at the high frequencies then low ones, hence the uneven slope of the line.

Hearing aides help by amplifying the problematic frequencies, or in the example above, by raising the red line back up on the right hand side. People with “profound” loss, though (which is rated even beyond severe) have too little signal to work with and thus amplification from an aide will not help. That is where Cochlear Implants come in.

I thought this was an interesting way to help visualize the differences, even if Fred was being a jerk…

Auditory Brainstem Implants

I read an interesting article this morning about a study starting up in Boston that uses Auditory Brainstem Implants (ABI) on infants that are not eligible for Cochlear Implants. This was particularly interesting to me because (1) I had no clue what an Auditory Brainstem Implant actually was and (2) the possibility that Fiona might not be eligible for a Cochlear Implant hadn’t yet occurred to me (cue latest mini-freakout).

So I did some research and here’s what I found: In less then 1% of deaf individuals, the actual auditory nerve from the cochlea to the brain is damaged or nonfunctional (from wikipedia). If you saw my post on Cochlear Implants, you’ll see that the CI works by connecting electrodes into the inner ear and through the cochlea, bypassing the damaged ear “hair cells” and stimulating the auditory nerve directly, which then carries the signal to the brain. If the auditory nerve is damaged, then a CI can’t work.

This is where Auditory Brainstem Implants (ABI) come in. They work very similarly to the CI, but instead bypass the cochlea and auditory nerve to stimulate the brainstem directly, as shown below:

Auditory Brainstem Implant

Auditory Brainstem Implant

So why don’t people just do the ABI?

Well first of all, you’re now talking brain surgery so the complexity, risk and cost of the procedure is much higher. Secondly, the effectiveness (in terms of spoken word understanding) is at best equal to CI, and often less. So in other words, more risk for less results. But, if no other options exist, this may be a last hope.

The scope of ABIs done is far less then CI: 1000 adults worldwide for ABI vs. 200,000 for CI. Also, until recently ABIs were only FDA approved for children over 12 years old. The study cited above is new in that it is being performed on infants, which should be interesting to watch.

As of today we don’t know the cause of Fiona’s deafness or if she would not be eligible for CI. Tomorrow we visit the ENT (Ear, Nose, Throat) doctor for the first time, and while we don’t expect to have all the answers then, we do expect to know the next steps.

Fiona At 6 Weeks

Fiona At 6 Weeks (Yesterday)

The Bionic Man

Cochlear Implants

The Bionic Man

The Bionic Man

Wow. Simply Wow. I had no idea. I feel like I’ve been living under a rock.

Cochlear (“koe-klee-er”) implants sound truly amazing. Here’s the wikipedia page, but my oversimplification is this: an electronic device is inserted into the skull to connect directly to the auditory nerves that transmit sound to the brain. This device, coupled with an external microphone, can transmit the sensation of sound to the brain, completely bypassing the nonfunctional aspects of a deaf ear. Freakin amazing, and best of all…it’s also called a BIONIC EAR. How freakin’ awesome is that?

Cochlear Implant Illustrated

Cochlear Implant Illustrated

My words do not do this justice though, so check out this 1 minute video.

Cochlear implants have been around for 20+ years now. Of course I’m an old fart – when I was a kid in the 70s/80s, they were not so common. I blame that and my lack of friends with hearing loss over the years for my lack of a clue here.

So now I temper my excitement with the caveats. This not a “cure” for deafness, the sounds produced are nowhere near as detailed as what a healthy ear can process. This video shows examples of what voice and music sound like through an implant. It’s both depressing and inspirational to me, depends on my mood. It’s fantastic that sound is now possible where only silence was before, but its depressing that the sound quality is still very low.

Still though, there’s hope:

  • In many cases this is GOOD ENOUGH to participate without assistance in society
  • The technology will ONLY GET BETTER in the years to come, quite possibly reaching parity by the time Fiona is a teenager! (and why stop there – let’s rev up the super powers now!)

To me the key is moving on this fast before Fiona’s language patterns start developing. Implants can now be done as young as 1 year old, well within the early learning plasticity stage, and we will definitely be hopping on that day one!

We’d love to hear more from people who have had experience with cochlear implants. Hundreds of thousands of implants have been done in the last 20 years, with the implant age getting younger and younger over time. From the videos we’ve watched, the earlier the better so one year old could be fantastic.

Of course, right now we just don’t know. Still so much to learn…

The Hearing Test

If you’re like me, you probably have no clue how you could possibly test hearing on an infant who can’t even speak. What’s even more fascinating is that they can test infants a DAY AFTER they are born! Incredible.

How does it work?

Well actually there are 2 different kinds of tests. The first test, conducted 1 day after Fiona’s birth and again a week later as a retest was called the Otoacoustic Emission (OAE) Test. In my layman’s non-medical understanding, what they basically did was insert a small probe into her ear that generates sounds and captures the “echo” back from that sound. They can then measure if that echo looks normal or not. Its pretty quick and non-invasive, provided the baby can stay quiet for 15 minutes.

All new infants receive this test today, but it is not uncommon to fail due to ear blockage from the birth. This is why we were not too concerned when Fiona failed her first (and even second) tests.

So after failing the first 2 tests, they pulled out the big guns 1 month after her birth. This was a test called the Auditory Brainstem Response (ABR) test. Basically it measures how sound introduced into the baby’s ear translates into electrical responses received by the brain. Here’s a great  explanation from MedicineNet.com.

The test is performed by placing four to five electrodes on the infant’s head, after which a variety of sounds is presented to the infant through small earphones. As the hearing nerve fires, the sound stimulus travels up to the brain. This electrical activity generated by the nerve can be recorded by the electrodes and is represented as waveforms on a computer screen. The audiologist can then present different loudness levels of each sound and determine the softest levels at which the infant can hear. For infant-screening purposes, only one sound is used to test the hearing, commonly referred to as a “click.” The click is a grouping of several sounds to test a wider area of the hearing organ at one time. The click is typically presented at a loud level and a soft one. If a healthy response is recorded, then the infant has “passed” the hearing screen.

Here’s what the equipment looks like (stock picture, not Fiona). As you can guess, “Fiona was not impressed” with this setup:

Screen Shot 2013-06-09 at 11.12.46 AM

ABR Response Test Equipment

Sitting through this test was not pleasant – it took about 3 hours to run, while you’re sitting there in darkness and silence watching the audiologist fidgeting with various graphs on a screen, all the while having little clue if the graphs are “good” or “bad”. In addition, the baby needs to remain quiet and still, which is an immensely taxing chore, especially for mom.

The screen the audiologist is looking at looks something like this:

Screen Shot 2013-06-09 at 11.30.13 AM

I don’t pretend to understand 1/100th of how this works, but I’ll tell you what I learned: they test each ear individually, measuring responses to different frequencies at different volumes (dB levels). Low frequencies (like the booming of a subwoofer) are easier to hear while higher frequencies (breaking of glass) are harder. This is why you can hear the ground booming when walking up to a concert well before you hear the singer, especially annoying teeny-boppers like Bieber…

During this test they are basically measuring 3 different variables:

  1. The frequency: can the infant hear some frequencies (base drums) better then others (glass breaking)?
  2. The volume (dBs): are some frequencies just “quieter” then others and can be amplified?
  3. The ear: is the left different then the right?

Each different graph captures a different combination of the above 3. I don’t know how to read those graphs beyond saying “the bigger the peaks and drops the better”. If the line is essentially flat, that means no response at all.

Most infants have various responses at various frequencies and volume levels. Some may look just fine, while others can be corrected by “turning up the volume”, which is basically what hearing aids do.

Fiona was flat at all frequencies and all volumes, in both ears. This means “profound” hearing loss, and something that is likely not correctable by hearing aids. (to be fair there was one low frequency in one ear that got a small result at very high volume level, but that could be an artifact of the testing precision. We’ll know more in a later retest).

The good news is there are now options (beyond sign language, which is also awesome) for profound hearing loss in the form of cochlear implants. I’ll talk more about that in a future post, but we’re very excited there.

Hearing loss is the most common birth defect today. I had no clue. Apparently 3 out of 100 babies have some level of hearing deficiency. This is why they test so early now – and it is true wisdom. Babies begin learning language within their first 6 months. As you can imagine, hearing is a huge component of this, and the earlier you are aware of the problem, the sooner you can act on it to help speech develop normally.

In this regard we feel truly fortunate. Knowing for sure within 1 month (1 month!) after birth has set us on a course NOW that we’d likely not have otherwise started until 1-2 years old, well past the start of language learning. This makes me much more optimistic in our ability to educate her well in these early stages.