INNOVATOR: HEARING
What parents of a deaf child want—what most parents want—is a normal life for their son or daughter, a life without special schools, sign language, or the social problems that can come from not being able to speak or hear clearly. Anil Lalwani is working to give parents exactly that.
A surgeon at the New York University Cochlear Implant Center, Lalwani is treading uncharted ground, placing cochlear implants in children as young as 9 months old.
Hearing aids can amplify sound to overcome so-called conductive deafness (caused by a blockage in the middle or outer ear), but they can’t correct nerve deafness (caused by problems with cells that transfer sound to the auditory nerve in the cochlea in the inner ear).
By developing a new way to screen for the genetic mutation most responsible for nerve deafness, Lalwani is able, in many cases, to skip the standard six-month hearing-aid trials and begin treating the cochlea right away. Early intervention is essential. “Normal kids start saying words around 1 year,” Lalwani says. “If you implant them much after 18 months or 2 years, you’ll miss the period where they can best acquire speech and language.”
If nerve deafness is the culprit, Lalwani may attempt an implant. The surgery involves drilling through the bone behind the ear and attaching a set of wires and electrodes to the cochlea. One end of the implant is connected to the auditory nerve; the other end is connected to a receiver placed under the skin, behind the ear. A small microphone and processor (the deviceresembles a hearing aid) are then placed behind the ear. The microphone gathers sound, and the processor converts it to sound waves. The waves are transmitted through the skin to the internal receiver, then travel through the implant to stimulate the auditory nerve.
Studies done by Lalwani and his colleagues at NYU show that all implanted children gain some degree of hearing; 90 percent of them can hear sounds as quiet as whispers. Of the children who receive implants before the age of 2 and immediately enroll in oral-language training, 85 percent are on par with their peers by the time they are 6 or 7 years old.
As the children grow up, the only visible sign of their implant is the behind-the-ear-microphone and processor. “If you go to a mainstream classroom without prior knowledge,” says Lalwani, “you can’t distinguish a kid with normal hearing from a kid who has an implant.”
Lalwani once visited a preschooler whom he had treated at 18 months. Without the implant, she wouldn’t have been on the stage, he says. “But I saw her in a Thanksgiving play. She had lines!”