Amid the shouting and arm-flailing of the Senate's Panama Canal treaties debate, few things attracted more attention yesterday than a nonevent - the failure of Kentucky's Democratic Sen. Wendell H. Ford to speak.

On Tuesday, Ford announced that he would take the floor yesterday to reveal whether he will be among the "yeas" or "nays" when the first of the two treaties comes up for a final vote this afternoon.

But, shortly before Ford was due to make his announcement, his office quietly informed the Senate leadership that he was canceling his scheduled 15 minutes of floor time. Instead of the verbal cut and thrust of the debate, Ford had decided to sit out the day secluded behind the doors of his office.

He had good reason. Ford is among the roughly half-dozen undecided senators who will determine whether the Carter administration can muster the 67 votes - two-thirds of the 100 senators - required for approval of the treaties.

Yesterday, his suite in the Dirksen Office Building across from the Capitol was under almost continual siege by pro and anti-treaty forces seeking to win the heart and mind - and thereby the vote - of Kentucky's Junior senator.

The day of pressure began early, with the 7:15 a.m. arrival at Ford's office of Vice President Mondale. Shortly afterward, Mondale was joined by two more of the White House's lobbying heavyweights, Robert S. Strauss, the president's trade negotiator, and Hamilton Jordan, Carter's chief political adviser.

Their message, Ford confided in an interview later, was plain enough: the president would be most grateful if a fellow Democrat and southern like Ford could look deeply at the issues and realize that a vote for the treaties is a vote for the national interest.

"They told me that what's at stake is a test of whether the president will come out of the treaty vote with enough strength to negotiate credibly with the rest of the world in the future," Ford said.

The same message, he added, had been conveyed by Carter himself in phone calls Monday and Tuesday. In addition, Ford said, "the president told me I have a standing invitation to come over to the White House and talk anytime I feel like it."

The early morning attentin from the White House team was only the opening salvo. Shortly thereafter came a phone call from Sen. Abraham A. Ribicoff (D-Conn.), a long-standing treaty supporter, and then, even more significant, Sen. Russell B. Long (D-La.) dropped by for a lengthy chat.

Long yesterday broke his own uncommitted stance to declare for the treaties. His call on Ford, the Kentuckian said, "was to try and convince me that he knew the problems I'm facing because he comes from a state where there is strong opposition to the treaties, like in Kentucky."

"But," Ford continued, "he said that, after 30 years in the Senate, he's learned that there are times when you've got to go against your constituents because you know it's in the larger national interest."

Ford, whose past statements have caused Senate headcounters to consider him as leaning against the treaties, wouldn't say that his visitors were causing him to reverse field. But he did admit that they had given him pause.

"I had fully intended to make a statement today," he said. "After the visits I've had, though, I decided to take a step back and look at it again."

However, while Ford huddled with his aides pondering "one of the toughest decisions in all my political life," those on the other side of the canal fight were training their guns on the senator.

Throughout the day, Ford's office assistants filed in and out carrying armloads of telegrams and letters from all parts of the country, urging him to vote against the treaties.

In the outer reception room, the switchboard buzzed with calls that seemed to represent every area code in the phone book.Those from Kentucky were fielded by the senator's hard-pressed staff, while callers from other states were asked politely if they would like to be transferred to another senator.

Through it all, Ford stayed in the background, quietly pondering his decision. His doubts about the treaties, he said, are rooted in concern over whether they provide adequately for U.S. defense of the canal after Panama assumes control in the year 2000 and the financial cost involved in the transfer of the canal.

In addition, he said, "I'm frankly bothered by the fact that the majority opinion in my state - indeed in most other states - is opposed. I have to ask myself if we're listening to what the people want - whether we'd be reflecting what the people are saying if we vote for treaties."

Some administration sources said privately that they believe Ford also is miffed at the White House because of differences about the administration's position on the use of coal, a major Kentucky resource, in its energy program.

These sources said Ford recently had refused to accept calls from Frank Moore, the White House's chief of congressional liaison, and speculated that he might be using his canal vote to wring concessions on the energy disputes.

That was denied strongly by the senator's staff. Ford himself said only that his treaty vote would be determined by "the merits of the issue."

"In the end," he said, "you can get all the advice in the world; but those who give you advice don't vote. That's why I'd like to stay out of the line of fire and think this thing through calmly and quietly for the next few hours."

However, it seemed unlikely that he would get that wish. By an ironic twist of timing, last night was the annual Democratic congressional fund-raising dinner - an event of which Ford is cochairman.

So, at the end of the day, Ford found himself heading not for some quiet, contemplative retreat but for the grand ballroom of the Washington Hilton Hotel, where many key administration officials, including the president himself, would be present and probably tempted to apply one last round of pressure before today's vote.