Several angry citizens called Fairfax City's City Hall yesterday to complain that the city's new mayor had "disgraced himself" and his office in front of 20,000 people. But Mayor Frederick W. Silverthorne swears up and flag on the Fourth of July.

Those familiar with the mayor's first public speech since assuming office said the problem was caused by Silverthorne's failure to plug his ears.

In the Fairtax high school stadium, jammed with people Tuesday night for the annual Fourth of July program and fireworks. Silverthorne delivered a halting, stumbling, garbled speech that made the audience laugh and the mayor's friends wince.

"It was," the mayor said yesterday, most embarrassing."

The problem was a public address system, long loathed by Fairtax City politicians that produces feedback and forces the speaker to listen to his ownwords just at the point when he is continuing to speak. Silverthorne said he was't prepared to handle it.

One way to fight feedback is to stick your fingers in your ears. Other speakers at the stadium Tuesday night did just that. "But," said a spokesman for Fairtax city, "you can't have the mayor sticking his fingers in his ears."

The mayor approached the podium, took out his notes and then joined two other people in chasing his notes around the podium after they were picked up by the wind, witnesses said.

Five City Council members contacted yesterday said they could heads or tails of what the mayor had to say. "Obviously, I was a little shook by the experience," Silverthorne said. "I wasn't bombed at all. I was trying to go slow in my speech and it took me a while to figure out that the answer is not to pay any attention to my words coming back at me."

Silverthorne, who campaigned this spring on a promise of cooling tensions between Fairfax City and surrounding Fairfax County, said he did vowed: "If I talk down there (at the stadium) again, I'm going to put a plug in my ear."