NEW HAVEN, May 7— On college campuses throughout the New York metropolitan area, the old clickety-clack of typewriters increasingly is being replaced by the whir of computer terminals.

Writing term papers, preparing study notes, taking exams, composing resumes and queries to prospective employers - activities that are at their peak as the school year draws to a close - are all becoming computerized activities.

''It's like a lot of inventions,'' said Lisa Valentovish, an 18-year-old freshman at Yale University, ''at a certain point, you can't even imagine life without it.''

College seniors say the transition to the computer age in education has been startlingly rapid. More than a few freshmen take computerized work and play for granted, having begun using terminals in high school.

''Five years ago, computers were used basically by scientists and quantitative social scientists,'' said Richard C. Ferguson, the associate provost of Yale. ''Now, it's fair to say that the computer is a general-purpose tool for just about anyone.'' Campus Computer Rooms

Miss Valentovish was sitting in a windowless room crammed with rows of computer terminals. The room, one of several set up by Yale for use by students, is open 24 hours a day, seven days a week.

Similar rooms have been established on many campuses in New York, New Jersey and Connecticut.

Almost all university students in the United States now have some access to computers, according to Anne Wujcik, director of educational research for Talmis, a market-research concern specializing in computers at schools. ''But the amount of access still varies dramatically from college to college,'' she said, with far greater access at the wealthier, more prestigious and technological institutions.

The primary benefit of using a computer, many students say, is that it makes tasks like writing a thesis or preparing for an exam quicker and physically simpler.

''Before, when you had a paper to write, you had to do a draft, cut and paste or cross out and scribble between the lines, then type it all over again,'' said Patrick Melnick, a 22-year-old Yale senior majoring in economics. ''With a computer you can refine your paper down to the smallest details without all that effort.'' Computerized Cramming

To prepare for tests, some students now collectively feed their notes into a computer, using key words to cross-reference and pull the information together. The computer can then be used to organize the results with headings in different typefaces before multiple copies are printed out or distributed electronically.

''I know a few people who bring portable computers to class to take notes with,'' Mr. Melnick said.

Inevitably, perhaps, computers have become something of a campus status symbol, not unlike owning a hi-fi or jalopy in days gone by. Although computer sales have been brisk over the last couple of years at such Ivy League schools as Yale, Princeton and Columbia, researchers at Talmis estimate that only about 12 percent of American college students today own computers.

The major obstacle is money. Although schools are increasingly working out arrangements to sell computers to students at reduced costs, prices still begin at about $1,000.

''It's become a way to distinguish between the haves and have-nots,'' said Kevin Costello, a 22-year-old Yale geology major, who lives in a dormitory suite in which five of seven students qualify as haves. Computer Byproducts

Amid the praise for the educational and recreational uses of the computer, there are a few skeptical voices.

''I think there are real assets and real detractions,'' said Donald Faulkner, a Yale creative writing instructor. ''In regard to writing, it certainly helps revision, which is a very important part of the process. But I also think that computers tend to make students verbose.''

A few students have discovered that cheating can be facilitated through creative computer use.

Computers are also being used to spark new acquaintences. At a ''Computer Dating Dance'' at the State University at Stony Brook, L.I., recently, ''ideal mates'' were matched through a computer program.

John Yom, a Stony Brook junior, met Gloria Kim, a sophomore, at such an event. ''If it wasn't for the computer dance, we probably wouldn't have met,'' Mr. Yom said. They have been dating ever since.

photo of Trevor Tarr (NYT/Rollin A. Riggs)