Science Friday is premiering a new series that follows the innovative research of women scientists. The first episode follows Dr. Rene Gifford and her colleague Dr. Allyson Sisler-Dinwiddie who together developed methods to improve cochlear implants. Science filmmaker Emily Driscoll brings us the story of how these scientists turned an accident into an opportunity for innovation.
Hearing a whole new world
Science Friday is premiering a new series that follows the innovative research of women scientists.
The first episode follows Dr. Rene Gifford and her colleague, Dr. Allyson Sisler-Dinwiddie, who together developed methods to improve cochlear implants.
Science filmmaker Emily Driscoll brings us the story of how these scientists turned an accident into an opportunity for innovation.
My name is Ally Sisler-Dinwiddie.
I'm a pediatric audiologist here at Vanderbilt.
Being an audiologist, it'll send me from the schools to the clinic, back to the OR doing cochlear implant surgery.
My job is to check the integrity of that cochlear implant before the surgeon implants the device.
When I was young, my hearing was tested for the very first time, and we walked away with hearing aids.
I had hearing loss growing up, but the car accident made it so much worse.
I remember my father saying to me, 'Ally, promise me that you will never, ever let your hearing loss get in the way of anything you want to do.'
In 2003, I started my first year of graduate school with my hearing aids, but between my first and second year, I got in the car accident and there was no more sound.
That's when I realized I want to try to find a way to keep on keeping on.
I want to be an audiologist, and there's got be a way.
Ally had basically almost no sound detection whatsoever.
We're talking about the most severe types of hearing loss.
My name is Rene Gifford.
I run a large research program.
I teach in the graduate school program here.
I also direct a large portion of the clinic, I see patients.
I was actually raised by my grandparents.
My grandmother incurred very severe hearing loss during World War II, and so you had to speak loudly, you had to speak clearly, you had to get his attention.
It absolutely shaped sort of my desire and my interest that would come into play many years later.
He wants you to be looking forward.
Like Tim said, you want to look straight until the noise is played.
Ready, bearing go to white 5 now.
Helping people who have hearing loss is pretty complex.
We've got the outer ear, of course, that everybody's familiar with.
You got the ear canal.
At the very edge of the ear canal is the tympanic membrane or as we call it, the eardrum.
Connected to the tympanic membrane are the three smallest bones in the body.
The very smallest bone in the body is then connected into the inner ear.
The inner ear is the cochlea.
Within this cochlea, it's three small chambers that are filled with highly conductive fluids.
And then you have a number of hair cells, and their vibration creates this electrochemical reaction through the auditory nerve and then ultimately up to the brain.
When I was 25, I started losing my hearing, and for no reason at all, pretty much.
The most common type of hearing loss that we see is the deficit of the cochlea.
It's a deficit of those hair cells that are dysfunctional or completely destroyed.
As hearing loss gets worse, you lose the ability to piece things together.
There's just not enough information.
The cochlear implant definitely has the ability to provide sound, a very different kind of sound.
It's an electronic device, but it's in the brain where all of the magic really happens.
Cochlear implants bypass the outer and the middle ear entirely.
The actual implant itself is placed beneath the skin, and then the electrode array enters the cochlea through the middle ear.
Each of those individual tiny electrodes are actually stimulating auditory nerve fibers from within the cochlea itself.
That device receives input from the external processor that's worn on the outside of the ear.
This is connected through a magnet.
When I got my first cochlear implant, I went from nothing to a world that's so far beyond what my hearing aids were ever able to provide.
I had no idea how much I missed growing up.
Cochlear implants are a miraculous technology, but when you stimulate an electrode, even though you're wanting to stimulate just a narrow population of cells, what happens is it spreads.
It's got kind of a background noise I hear when I'm talking.
We know that's one of the biggest culprits for why our patients struggle for communication and noise, why they struggle with music perception.
So a piano would sound a little different, or, like, a violin would sound different.
If you think of electrical spread of activity causing a smearing of the incoming frequencies and pitches, more could potentially be less.
Now with the cochlear implant, you can see the electrode array as you're inserting it, but beyond the first turn of the cochlea, you're basically blind.
The engineering group was looking at 3D reconstruction of the internal ear, and we just kind of said, we know the distance between each one of those electrodes and those neuron targets that we're trying to stimulate.
Now let's selectively deactivate some of those electrodes.
What we have suggested is turning off 6, 9, and 10.
Fewer number of electrodes, but the right ones.
It was sort of like one of those literally aha moments that you get a handful of times in a career.
We'll take everybody's individual anatomy and function and really develop a cochlear implant program that can maximize their hearing capabilities.
I had heard this research was going on.
I was here on staff, but as a patient, to hear that we're going to turn stuff off, even though I know, even though I knew it was going to be for the best, I was very nervous.
Ally was the first or second participant.
I kept thinking, we are all here to make this experience better for everyone else.
If we don't do this, we will never know.
With her, I recall it was just two electrodes we deactivated.
I turned off those two electrodes and she said, 'It's like you took a pillow off my head.'
That program ended up being so far beyond my other program that I had before.
I am, like, very much a skeptic.
You know, I just -- unless I see data, I don't believe it.
So she came into the lab.
At her baseline, she was getting about 38% word recognition.
And we just ran that test again.
She was at 88% overnight, by just turning off two electrodes.
We were just so excited.
So it's been four years.
The number of patients that have been able to take part in this, it has gone on and on, and so they're not going to stop here.
Okay. So you're ready?
An activation can be a very emotional experience.
This is something they've been waiting for.
They've had surgery and now they want to know how well it's going to work.
So I'm going to have you just turn around and talk to your parents and just kind of see what their voices sound like, and kind of get used to the sound.
You sound the same.
I sound the same?
You remember my voice?
[ Laughs ]
Can you hear me now?
Is it the same?
Is it better?
I love it.
I mean, that's the moment.
[ Laughter ] One of the goals is to try to get this technology into the hands of people who need it.
The Mama Lere Hearing School at Vanderbilt, we've enrolled about 30 children, and the children actually show even greater outcomes than the adults.
Okay, and this...
And we are really hopeful that in the future, we'll really develop a cochlear implant program that can maximize their hearing capabilities.
[ Laughs ]
The patients that I have the opportunity to see every day, help me just as much as I'm hopefully able to help them.
Let's put it on your head first.
What a role model for these little patients of ours who see that, 'Gosh, look, Dr. Ally's got implants just like I do, and I can grown up and I can help other people, too.'
I mean, we couldn't ask for a better job.
Everybody's got challenges.
Everybody's got things that they want to overcome.
It's just all about your perspective.