The sound of Sammie Hicks's own breathing moved her to tears three weeks ago.
That's because it was the first time she ever heard it.
"I started to cry because it was overwhelming," 10-year-old Sammie told ABC affiliate WFAA. "I had no idea what the sounds were."
Born with a genetic mutation that caused her to lose her hearing as a toddler, Sammie was fitted with a cochlear implant – a kind of bionic ear that simulates hearing – and documented the process in an online video diary over the past several months.
In a video posted Wednesday from her home in Collin County, Texas, Sammie mimes robot arms and flashes a braces-clad smile when her mother asks what the implants sound like to her. The implants don't exactly mimic hearing, so Sammie thinks voices sound like robots.
Unlike a hearing aid, which amplifies existing sounds, the cochlear implant is designed to directly stimulate the auditory nerve, bypassing the damaged part of the ear. First, an implant is surgically placed beneath the skin. Three weeks later, it is turned on and works with an earpiece to process sounds and stimulate the nerve.
"When a cochlear implant is turned on, people will hear things they've never heard before," said Dr. Jennifer Smullen, who has performed hundreds of implant surgeries at Massachusetts Eye and Ear Infirmary. "It's like someone who really needed glasses, put them on and realized they were missing the sunset."
Hicks's new favorite activity is taking long walks outside so she can listen to the birds, her mother, Jenifer, told ABC News. Other sounds are more annoying, on the other hand, like the air conditioner and the sound of her classmates turning pages.
"She wasn't expecting school to be quite so loud," Jenifer said. "She can hear everyone eating their snacks and writing on paper. And she can hear them breathing."
Sammie's younger brother, 9, went deaf "rapidly" over the last two years and just had the same cochlear implant surgery, Jenifer said. His implants will be turned on June 7.
"When we brought him home from surgery, she broke down in tears because she knew what he was going through," Jenifer said. "She wouldn't leave his side."
In yesterday's video diary entry, Jenifer asked Sammie if she had any advice for her brother.
"After it gets turned on, it's not going to be what you expected, of course," Sammie said, followed by a few more robot sounds. "If you jump around, the thing will fall off. "
Samie's brain learns how to process the information from the implants every day, Smullen explained.
And as she learns, she'll update her video diary and share new sounds with the world.