Ken Stehle heard his daughter, Ashley, for the first time at her choir show. Villa Duchesne High School/ABC News

Ken Stehle expected to see his 14-year-old daughter at her choir show, but he did not expect to hear her. Stehle has been deaf since birth.

His daughter Ashley was a surprise soloist at the Show Choir Christmas Concert at Villa Duchesne and Oak Hill School in St. Louis, Mo., and thanks to an advanced level of power hearing aid technology he was able to hear his daughter serenade him.

"When Ashley came out, she dedicated it to her dad," Brenda Stehle, Ashley's grandmother told ABC News. Ashley was wearing a microphone and her father was wearing a remote mic bundle to receive her audio.

"He just closed his eyes and he had the biggest grin you ever seen in your whole life," she said. "He was concentrating on hearing the sound of her voice."

"Ken was just fascinated," Brenda Stehle said. "He just kept saying, 'Awesome.'"

"After Ashley finished her song, she busted out in tears and so did her dad," Mrs. Stehle said.

The crowd gave Ashley a standing ovation.

Ken Stehle, 49, was able to hear his daughter sing because he received a Phonak Naida Q70 hearing aid the Friday before his daughter's choir show on Dec. 8.

Rene Gifford, director of the cochlear implant program at Vanderbilt Bill Wilkerson Center, praised the Naiad Q70 as cutting edge technology that has only become available in recent months.

"It's the first time cochlear implant recipients have been able to take advantage of true Bluetooth technology without any conversion factor and is a much more convenient way to connect assistive listening devices," she said.

Ashley's immediate and extended family all gathered together for Ashley's show. Mrs. Stehle said the show director came onstage at the end of the show and announced there would be a surprise for someone in the audience. That surprise was Ken.

"Ashley was not announced as a soloist prior to the concert, so it was a surprise in more ways than one," said Elle Madras, from the communications department at Villa Duchesne. She estimates more than 350 people were in attendance.

Ashley was the last solo performance before the final ensemble number, Madras said.

"Ashley performed a twist on the 1960's classic, "Christmas (Baby Please Come Home)", personalizing the lyrics for her family," Madras said. "There was hardly a dry eye in the house."