CNN’s Chris “Fredo” Cuomo called his mother on live television in an attempt to prove President Trump wrong, but his endeavor backfired significantly.

David Holmes, a political officer at the U.S. embassy in Ukraine, is testifying before the House Intelligence Committee on Thursday. His account is largely based on a July 26 phone call he overheard between the president and Ambassador Gordon Sondland.

“It was quite loud when the president came on, quite distinctive,” Holmes claimed, noting that Sondland supposedly “held the phone away from his ear”:

In a tweet on Thursday, Trump doubted Holmes’ ability to properly hear the entirety of the conversation.

“I have been watching people making phone calls my entire life. My hearing is, and has been, great. Never have I been watching a person making a call, which was not on speakerphone, and been able to hear or understand a conversation,” he said.

“I’ve even tried, but to no avail. Try it live!” he added:

In a desperate attempt to prove Trump wrong, Cuomo called his mother on live TV.

“Let’s just play with that for a second,” Cuomo said of Trump’s claims. “Mom, can you hear me? Alright.”

“So if I were holding the phone here, I’m with Dana Bash, you know how you’re always telling me to let her talk because she’s so smart and I shouldn’t say so much? Can you just say hello?” Cuomo said to an awkward moment of silence.

“Mom. She probably can’t hear me, ” Cuomo told Bash, quickly turning his phone on speaker.

“Yes, I hear you. When you talk to me, I hear you,” Cuomo’s mother said, essentially disapproving her son’s theory that she did not respond because she could not hear him. Rather, the audience did not hear her response, because his phone was not on speaker, thus demonstrating the president’s point:

“I’m talking to you. Say hello to Dana Bash,” Cuomo said, appearing to press another button on his phone. It is likely, in that moment, that he took his phone off speaker, given how the remainder of the conversation went.

“Hi, Mrs. Cuomo. How are you?” Bash asked.

Her question was followed by silence. It seems Cuomo’s mom was answering the question, but her voice — not on speaker — was completely unintelligible and ultimately resulted in what amounted to another awkward moment of silence for CNN viewers.

“Alright,” Cuomo said, hanging up.

“This is not on speakerphone. It’s regular phone. It’s two feet away from Dana; she can hear my mother. I’m not sure mom can hear us,” Cuomo said in response to another individual sitting at the table who said, “I can’t hear your mother, Chris.”