PAT SUMMERALL and Tony Trabert raised silence on television to a new art form by the sparse commentary they recently offered during CBS Sport's coverage of the Pepsi-Cola Tennis Tournament.

Unlike the tennis commentary we have had to endure from the likes of Bud Collins and Julie Heldman, Summerall and Trabert spoke sparingly. But when they did speak, they aided rather than irritated us.

After all the non-stop prattle that the network news commentators offered us during President and Mrs. Carter's walk down Pennyslvania Avenue, I began to think they were seeking to challenge sports announcers for sole possession of TV's award for packing the smallest amount of thought into the greatest amount of words.

That would take some doing. Howard Cosell alone merits permanent possession of the award solely on the basis of his non-stop commentary during the boxing matches at the Montreal Summer Olympics.

I sometimes wonder if the people who run the networks appreciate how much the excessive verbiage of their commentators offends the viewers who watch news and sports programming. There's real anger out in videoland about the seeming incapability of TV commentators to hold their tongues during the transmissions of events that generally speak for themselves.

It is generally accepted that these worthies receive a generous wage for exhibiting their excitement when confronted with the obvious. But from the amount of verbal excess they shoot off in our general direction during conventions, inaugurations and sporting events, one would think they were all being paid space rates - so many dollars for every word they utter.

They don't seem to understand the power of silence. English diplomats learned it a long time ago. The late Herbert Butterfield, a professor of history at Cambridge University, had this theory that the English invented the round-table conference at the end of the last century as a device to disguise to the world that their military and economic power was lessening in the face of challenges by German and other nations.

Taking Butterfield's theory one step beyond, I've always thought that English diplomats fell asleep at these conferences to intimidate their opposite numbers. The lesser breeds - those who were not English - would look across the table and think perfidious Albion and wonder what the English dogs were up to. Most often they weren't up to anything. They were just asleep. They simply understood that not only was silence golden but in their case it was sterling.

Because I agree with John Kenneth Galbraith's view - expressed in "An Ambassador's Journal" - that modesty is a highly overrated virtue, I here recount a personal experience with the power of silence.

I was standing on a platform that NBC News had erected at Arlington National Cemetery on the Saturday night in June 1968, when Robert Kennedy's body was brought to the Cemetery from Union Station.

As his casket was slowly being borne up the slight incline to the place where he would be buried, I thought of what I might say. But there was nothing I nor anyone else could say at that moment. So I said nothing. The silence lasted about 17 minutes. Some say it was the longest period of sustained silence they could ever remember on television.

A number of people said the silence was very dramatic. Others said it was highly disturbing. Whatever it was, it was occasioned, not by design, but by the inability to say anything that would improve upon the power of the picture.

I am not trying to be a nag. But I do wish that my former colleagues would conduct a survey among their viewers on how irritating is this senseless and rising level of noise pollution. They would be surprised at how outraged people are about it.