Children who have been deaf for their entire lives are receiving the gift of hearing for the very first time thanks to a device being tested by researchers across the country.

It’s called an auditory brainstem implant (ABI), and it’s a surgically inserted electronic device that provides a sense of sound to people who are profoundly deaf due to retrocochlear hearing impairment auditory nerve damage caused by injury or illness. The technology is similar to cochlear implants. But instead of applying electrical stimulation to the cochlea, the auditory portion of the inner ear, the newer implants stimulate the recipient’s brainstem.

Consisting of a tiny radio receiver inserted under the skin and minuscule platinum electrodes implanted in the brainstem, the prosthetic hearing device stimulates neurons directly at the stem, completely bypassing the auditory nerve.

Maggie Gleason, 14, who was born without cochleas, recently heard sound for the first time in her life when hearing specialists at University Hospitals (UH) Case Medical Center in Cleveland, Ohio gave her an ABI. One of Gleason’s surgeons, Maroun Semaan, told WKYC that the teen may be the first recipient of ABIs for missing cochleas.

For someone who has never heard, the perception and awareness of sound is extremely helpful, said Dr. Semaan.

What do Gleason and other children implanted with the devices hear for the first time? The Associated Press asked audiologist Laurie Eisenberg of the University of Southern California, a longtime leader in ABI research involving children, what recipients experience when a whole new world is opened up for them.

She isn’t going to be hearing like a 3-year-old,Eisenberg said of Angelica Lopez, a toddler born without functional auditory nerves who was fitted with one of the revolutionary devices. She’ll be hearing like a newborn.

Lopez cried the first time her device was switched on, not out of joy, but because she was afraid of the bewildering new sense she suddenly possessed. Five months later, she is using sign language to identify certain sounds she hears, like a cough or a dog’s bark. She is also beginning to babble like a baby, with speech therapists working to improve her vocal abilities.

In Gleason’s case, her father’s low voice was heard most clearly.

I always felt I would have a lot to say to her when the moment came, her father, Frank Gleason, told WKYC. But I was left speechless.

ABIs aren’t new. They have been around since the late 1970s, when pioneering Italian doctor Vittorio Colletti began implanting them in deaf adults, and they have been approved by the US Food and Drug Administration (FDA) for use in adults since 2000. But in recent years, researchers have been exploring the exciting possibilities for the devices to give the gift of hearing to children who have never known it.

Hundreds of children in the US can benefit from ABI surgery, Mark Krieger, a pediatric neurosurgeon at Children’s Hospital Los Angeles who also is associate professor of clinical neurological surgery at the University of Southern California’s Keck School of Medicine, told USC News.These children would otherwise never hear or develop verbal speech in their lives.

There are, however, significant risks.

We are talking about real surgery to go into a deep area of the brain, Dr. Marc Schwartz, a neurosurgeon with the House Clinic and Huntington Medical Research Institutes in Los Angeles who is part of the USC study, told the AP. This is a precise operation that requires exacting technique.