WILLIAMSBURG — When her only child was 3 years old, Judith Feldman woke up one day to find he'd lost his ability to speak — except to ask her, "What's your name?"

"He'd been on the tennis court the day before it happened, like this stroke," Feldman said of her son Rio Wyles, who grew up in Venice, Calif. "I felt like I was losing him. I was devastated."

Doctors diagnosed Wyles with autism and warned Feldman and her husband that their son may never mature or reacquire language — but Wyles shattered their prophecy.

"He was in the Tower Records store and he said, 'I want to be in the music business.' It was one of the first sentences he'd ever said," Feldman recalled of when her son was 8 years old.

"He said, 'I want to be a rapper and have my own label.'"

Wyles, now 21, has spent years creating and performing tunes about overcoming his struggles — and this week he flew across the country for his first recording session in Williamsburg with New York band Timeflies.

"All the docs said I couldn't do it, but now they have to face the music," Wyles rapped in his black T-shirt and sunglasses at the Converse Rubber Tracks studio.

In the session — made possible by a partnership between the autism advocacy organization Autism Speaks and Converse sneakers' recording studio — Wyles (known as Soul Shocka) gave Timeflies' hit song "Swoon" his own twist.

"It's about how I got from the bottom to the top," said Wyles of the rap he wrote "in about 10 minutes" a few days earlier back in Southern California.

To Wyles' parents — who accompanied him to the session Monday and beamed with pride as he recited his catchy lyrics — their son is the ideal "voice for the voiceless," who found a creative passion that reaped wisdom from his disability.

"The doctor said to find out what his obsession is, whether dinosaurs or trains. Fortunately, it was music," recalled dad David Wyles of his son's childhood and the hours spent in Tower Records picking out albums.

"He taught himself to read through music, reading lyrics."

Rio Wyles, who has seen a surge of success with recent performances at the United Nations' Autism Awareness Day and at the Miracle Project's Autism Sings for Cancer, is both an empowering and appropriate example for autistic individuals, said Liz Feld, president of Autism Speaks.

"There are so many autistic individuals with musical or artistic talent...and their expression comes out when they sing," said Feld, adding that Converse's recording studio worked well because it also promoted "freedom of expression."

For Wyles, who calls himself a "conscious rapper" who strives to create meaningful tunes, the writing process includes dictating lyrics to his parents.

"We meditate before he raps," said Feldman of their frequent practice. "I usually say I feel honored, rather than proud, to be his mother. But right now I also feel proud because he wrote this song in such a short time."

And for Wyles, the Williamsburg recording day offered a sense of accomplishment, devotion — and fun. "It's cool," he said of the session. "I'm in Brooklyn, a.k.a. 'BK,' a.k.a. 'Crooklyn.' It has a clean grittiness."

And as he let his sunglasses fall on his nose, Wyles grinned at his parents in the Hope Street studio and confessed quick attachment to the colorful warehouse-filled block.

"Do we really have to go back so soon to California?" he asked.