With videocassette recorders in about seven of every 10 U.S. homes, you might think that we're watching less and less television when it is aired and more and more television recorded and played back later.

But you'd be wrong.So says Ogilvy & Mather, one of the nation's largest advertising agencies.

Ogilvy & Mather culled a number of statistics from A.C. Nielsen Co., the market research firm, and concluded that although the number of VCRs in use has grown by record numbers in the past five years, individual VCR usage is down.

Indeed, the advertising agency says we're watching more television as it is aired than ever.

"The data indicate that in homes with VCRs, most of the viewing is done in the traditional way," says Kevin Burns, the ad agency's manager of media research. "The first people who bought VCRs tended to be video fanatics. But as it spread through the population, people don't use it that much for time shifting."

The agency also noted for its clients that the statistics provide no evidence that we are turned off by TV advertising or that we are using our VCRs to fast-forward through and avoid commercials.

We're not watching all the commercials that we tape. But we're not watching all the shows we tape either.

Nielsen says that of all the programming we record for later viewing, about 40 percent is never watched, including commercials and shows.

Impressive as that statistic is, it refers to a pretty small amount of television in general.

According to the Nielsen data, of all the television watched in U.S. homes, only about 1.5 hours a week, or about 3 percent, is taped and watched later.

That's a dramatic decline from about five years ago, when Nielsen reported that the average VCR owner taped 2.1 hours of television for later viewing.

Back then, VCRs were in only about 21 percent of U.S. homes. Now VCRs are in about 70 percent of U.S. homes.

In one respect, the statistics are understandable.

Owners report that when they first buy their VCRs there is a period when the machines are used constantly.

But as the newness of the electronic addition wears off, usage declines.

But Ogilvy & Mather found another curious aspect.

VCRs were not only expected to free us from network programmers by allowing us to record and play back anything we want when we want, they also were to allow us to abandon television commercials forever.

With our handy remote controls and a fast-forward button, we were supposed to be able to zap those little buggers, skimming over television ads and quickly getting back to the program.

But that doesn't seem to be what's happening. In fact, VCRs are used largely to show rental movies in the home.

Consumers clearly like to rent movies. Last year we spent an average of $75 a year per family renting tapes. But Nielsen estimated that the average home spends less than three hours a week watching a rented movie.

That compares to about 48 hours a week watching conventional television.

Nielsen says that overall, we watch more television than ever before, including real-time programming.

"Despite all the things people thought about the VCR - that it would revolutionize people's viewing habits, that it was a threat to commercial television - by and large it hasn't occurred," says Burns. "The medium today is still strong and vibrant. The VCR hasn't had any major detrimental effect on commercial television."VIDEO QUESTION

Q: My son bought a video in London. The clerk said it would play on American VCRs, but it doesn't. What can I do?

A: I'm asked this question more often than any other, and I try to answer it once a year. Right now European cassettes will not play on U.S. video systems, and conversion is prohibitively expensive. Next year could be different, when Panasonic promises to introduce an international VCR. - Andy Wickstrom (Knight-Ridder)NEW VIDEOS

THE NEXT VOICE YOU HEAR - God speaks to mankind by radio in this wonderfully sappy goose-pimpler about the bringing of harmony to planet Earth, especially the postwar American suburbs. Produced by Dore Schary and directed by William Wellman, this campy drama is appallingly dumb but somehow eerie. God's drive-time show is broadcast in French, English and a variety of languages, depending on who's listening where. Special bonus: Nancy Davis (Reagan) stars as Mrs. Average Housewife alongside James Whitmore, Jeff Corey and Lillian Bronson in this reverential parable on the small sins of the little people. 1950. 83 minutes. MGM/UA. $19.98. - Rita Kempley (Washington Post)

TOKYO OLYMPIAD - Kon Ichikawa's 1965 documentary on the 18th Olympic Games is one of the most compelling records of sport on film, and as an expression of the mind of the athlete it is unsurpassed. The film's greatness lies in the director's ability to abandon the conventional big-game, crucial-moment approach of most sports movies and concentrate on the stories within the Games. Watching it, what we identify with most in the athletes isn't their superhumanness but their concentration, their extraordinary effort and their fallibility. 170 minutes. 1965. R5-S8. $79.95. - Hal Hinson (Washington Post)

VITAL SIGNS - A group of student doctors enter their pivotal third year and leave the classroom to begin the hands-on segment of their education. Typical of ensemble proj-ects that dwell on the inner dynamics of a small group thrust into a stressful situation, "Vital Signs" presents us with a collection of archetypes. The movie is entertaining enough for those who prefer their fun to come in familiar trappings, but do we really need another project showing us how hard medical school is? CBS/Fox. - Tom Maurstad (Dallas Morning News)