ONCE WHEN I WAS a student, I sat in a drugstore drinking coffee with a friend. Her gaze kept wandering to the counter where a couple were seated, a storybook handsome couple, young and well dressed. They were drinking their coffee in silence.

"I don't envy the ones who are talking all the time," she said when she noticed me watching her. "It's the ones that don't have to say anything that I envy."

I didn't understand what she meant because I was young and inclined to be tongue- tied with strangers. Years later, I have to fight a tendency to fill any conversational void with words that come all too easily, any words I can lay my hands on to apply as a baand-aid to faltering communication. I am charged, it seems with the responsibility not to let strangers fall with me into a pool of silence in which we would flounder around together.

A friend of mine suffers from this obligation even worse than I. She hurls words into conversational lapses as one would rush sandbags to contain a flood. She is pretty and amusing, but in her company I have seen people sit hypnotized before the flow of words, caught like rabbits frozen in the glare of a car's headlights.

Yet she is only assuming what she understands to be the obligation of a responsible guest. Perhaps it is something in the training of us women, something lingering from the 19th century when we were raised as parlor ornaments with a duty to hide behind our fans and amuse the gentlemen.

I may learn to let a silence fall without feeling personally responsible, but it is not at all certain. "Surely human affairs would be far happier if the power in men to be silent were the same as that to speak," said Spinoza, and I am studying to take his words to heart.

I long to take a leaf from Macaulay, of whom it was said that his occasional flashes of silence made his conversation positively brilliant. It seems to me that silences are far too intimate to share with most people.

But it isn't only the lack of decent silences which lurks in the wings waiting to strangle conversation. It is the tendency of us all, struggling for our moment in the sun, to murder general talk. The evening was wonderful, I tell my hostess, but she shakes her head. It was nice, yes, but leaden. The mix was wrong; the guests did not strike flint from each other and draw each other out. She shrugs. Just another evening.

Talk is good or it is not, but the truly herculean test is the arrival of house guests. By their very nature, house guests are an exhausting pleasure. Long hours of talk await those who invite guests for overnight stays, and only the recess of breakfast offers promise of respite. It is widely understood that speech is unnecessary at breakfast, except perhaps to ask that the jam be passed. All can sit in blessed silence without a thought for convention.

Recently a friend reported that she and her husband had been snowed in with house guests during one of the season's worst storms.

"We played Scrabble from morning to night," she said sighing. "But it was the constant conversation that exhausted us. George and I don't usually speak much after dinner. But how can you say to a guest, "Here'e a book, I'm halfway through this one?"

The English, I understand, do guests of this sort best. Country weekends can be tiresome if everyone must chat constantly around the fire from breakfast to the nightcap. The English provide maps of the countryside with marked places suitable for walking, the names of interesting shops in the village and a goodly stack of books in the guest room. "We'll meet for lunch," they say, striding off in their stout boots on business of their own. Maybe we could learn something from the mother country.

Perhaps only lovers and those who have lived together long enough to be used to each other are comfortable with the sounds of silence. Maybe it is only they who can throw off the tyranny of the need for words. And, like my friend in the New York drugstore, I envy them.