New Hearing Technology Brings Sound To A Little Girl
RENEE MONTAGNE, HOST:
Next, we turn to something you're doing right now - hearing. For children born deaf in this country, cochlear implants are often the answer. Unlike hearing aids, they are surgically implanted devices, but they don't work for everyone. From member station KERA in Dallas, Lauren Silverman introduces us to one little girl who is trying a new hearing technology.
LAUREN SILVERMAN, BYLINE: Jiya Bavishi was born deaf. For five years, she couldn't hear and she couldn't speak at all. Now, all she wants to do is say hello.
JIYA BAVISHI: Hi.
SILVERMAN: The 6-year-old is bouncing around the room in a bright pink top. Her tiny gold earrings flash as she waves her arms and uses sign language to ask who I am.
LINDA DANIEL: Lauren.
SILVERMAN: Linda Daniel, a rehabilitative audiologist in Dallas, has been working with Jiya since she was a baby. At around 12 months, doctors gave Jiya cochlear implants, but they didn't work. To understand why, we have to take a quick trip inside the ear with the help of a 1940s educational film. Hearing originates here in the cochlea. It's the fluid-filled structure that looks like a small snail shell.
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UNIDENTIFIED NARRATOR: Let us look at the inside of this amazing little instrument.
SILVERMAN: Basically, as sound waves enter the ear, they strike the eardrum, causing it to vibrate. Those vibrations are carried through to that snail shell-shaped cochlea, which is filled not just with fluid but also tiny hair cells.
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UNIDENTIFIED NARRATOR: The ear then is a very delicate and complicated, mechanical device.
SILVERMAN: If the tiny hair cells in the cochlea are severely damaged, a cochlear implant can help by replacing them with electrodes. But Jiya's hearing problem wasn't the hair cells and so the cochlear implant didn't work.
DANIEL: You have to have a sufficient or healthy auditory nerve to connect the cochlea and the electrodes up to the brainstem.
SILVERMAN: Essentially, the connection from the cochlea to the brain for Jiya was too thin. There was no way for sounds to make that final leg of the journey and to reach her brain. Now, usually the story would end here. If cochlear implants don't work, you turn to sign language, and the Bavishis did. So for years, they communicated with Jiya through sign, but then they heard about an experimental procedure called an auditory brainstem implant.
DR. DANIEL LEE: This is a very rare procedure. So there have been less than 200 of these implanted worldwide in children.
SILVERMAN: Dr. Daniel Lee is director of the Pediatric Ear, Hearing and Balance Center at Harvard Medical School. In the U.S., he says auditory brainstem implants are approved for adults and kids older than 12 but not yet in younger children.
LEE: Surgeons in Europe really have pioneered the use of the auditory brainstem implant in children who are born deaf and can't receive a cochlear implant, and those data look pretty encouraging.
SILVERMAN: In 2013, the FDA approved the first clinical trial of the implant in children, and the Bavishis had to decide whether to apply to be a part of it. Linda Daniel says it was a big decision. It would mean placing a device in the 5-year-old's brainstem.
DANIEL: The family was at a real crossroads. Did they want her to really not have the option to hear for the rest of her life? Or did they want to make a very risky decision and have the experimental procedure done?
SILVERMAN: The Bavishis traveled from Texas to North Carolina for the surgery. The University of North Carolina is one of four institutions investigating the implant.
JINGA BAVISHI: Can you show your device?
SILVERMAN: Jiya's mom, Jigna, pulls back a purple headband to reveal part of device. There's the piece that sits on her ear, which works like a microphone to pick up sounds. That microphone is attached to a small, black magnet on the side of her head. What you can't see is what that magnet is connected to, and this is what makes it different from a cochlear implant. Below the skin, there's a receiver and down in the brainstem is a tiny microchip. So the sounds picked up from the microphone on her ear end up in the brainstem's microchip.
DANIEL: And it has two rows of electrodes, and each electrode is responsible for a band of frequencies.
SILVERMAN: From the low frequencies of speech...
DANIEL: Ah, oo (ph).
SILVERMAN: ...All the way to the high.
DANIEL: Sss, fff (ph). And if you put those all side by side, you pretty much replicate the frequencies of speech.
SILVERMAN: I mean, do we know what it might sound like?
DANIEL: I think we could assume that it doesn't sound crisp, distinct. It would take longer to learn to interpret the sound.
SILVERMAN: Doctors told the Bavishis not to expect anything for a year or two, but Jiya didn't take that long to start recognizing and mimicking sounds, like this one.
JIYA: (Mimicking toy car).
SILVERMAN: Jiya mimics the sound of an engine as she plays with a yellow toy car and then...
JIYA: Beep, beep.
SILVERMAN: ...Beep, beep, she says. Her mom, Jigna, smiles.
BAVISHI: Even though she's doing so good right now, we have to still be careful where we set our expectations.
SILVERMAN: Doctors will monitor Jiya over the next three to five years, studying how her brain develops and incorporates sound and speech for the first time. For NPR News, I'm Lauren Silverman in Dallas. Transcript provided by NPR, Copyright NPR.