America's professor are professing distress.

That was the prevailing sentiment at the four-day annual convention of the American Association of University Professors, which ended Saturday at George Washington University.

Beset on all sides by declining birth rates, fiscal austerity, changing student demands and a yearly deluge of new doctorates, college teachers are climbing down from the ivory tower and into the monetary mud-wrestling of budget politics.

Faced with a 20-percent erosion in faculty salaries during the '70s and a diminished public recognition of the profession, even professors who would prefer to think of themselves as classless aristocrats of the mind are now exchanging sodality for solidarity. As one West Coast scientist put it, "Whether I like it or not, I am labor and I'd better get used to it."

As the 400 convening representatives from around the nation conducted their orderly polysyllabic palaver in the Marvin Center, they ranged over subjects as diverse as new techniques for collective bargaining, the threat of the $30 textbook, the future of academic freedom and tenure and the status of women in higher education. And salaries (which average around $16,000 for a new professor and rarely extend beyond $36,000 for a venerable veteran) where only one topic in the humid air. Among the others:

A new consumerism among students. Many schools now have "right-to-learn" manifestos, and student demands have risen with tuition. "There's lots of demeaning stuff," said Collette Moser of Michigan State. "For example, pieing. Students have hired hit men to throw pies at teachers whose style, lectures or general arrogance they didn't like."

Shrinking public esteem. "We definitely have an image problem," said Robert Alan Fox of the University of Hawaii. "When I went to college, a university professor was a highly respected person," said H.W. Norton of the University of Illinois, who feels that respect has declined both because of the residual image of the revolutionary '60s -- in which higher education too often lapsed into post-teen day care -- and "movies like Flubber' that make fun of professors and their absent-mindedness."

Changing demand for courses. Fox, a physicist, has been obliged to teach "for the first time a course in astronomy, and to be candid I didn't know much about it. But it's one of the most successful courses I ever taught -- maybe because of that."

Declining students skills. "If I'm a professor of English," says Irving J. Spitzberg Jr., general secretary of the AAUP, "I'm going to have to teach basic writing. Chaucer may be my first love, but the simple declarative sentence may have to be my focus."

The growing use of inexpensive part-time faculty. John Craig, a chemist from the University of California system, calls them "nomads" who "threaten themselves directly and the integrity of the profession" by working in "unreasonable" conditions made possible by the glut of new doctorates every year. Fox blames the professorate for the surplus: "We probably are the only profession that sells a product that is in direct competition with itself. I don't see why knowledge can't take a sabbatical" for a few years.

But it was clear that the financial future was uppermost on the minds of those entering what Spitzberg calls "the valley of the '80s," with declining youths enrollments and faltering federal largesse.

"The Reagan-Stockman budget and the mini-versions of it in state houses across the country," Spitzberg told the general session of the 75,000-member organization's 67th meeting, "combine to pose the greatest challenge to quality and equality in American education since the Depression."

Spitzberg and 150 of his colleagues ascended Capitol Hill on Wednesday to argue the immediate threat of cutbacks in student loan programs and direct government grants. But in the long run, Spitzberg believes, professors will have to channel their "sense of anger" into "getting organized" and regaining the control of universities. They lost that control in the '70s: Old traditions of faculty governance died, and as the troves of academe ran dry, a new "mandarin class" took over, professional administrators "who don't actually research and teach."

Although college enrollments have remained reasonably constant (as more women and "reentry" adults join the student bodies), many administrators are desperate to rid themselves of tenured faculty. Some fire them outright, provoking the wrath of the AAUP, which this year censured two schools for doing so. Other are less drastic. At Michigan State, a "buy-out" plan offers professors two years' salary if they will leave. "It's the golden handshake," says Spitzberg, who sympathizes with the budgetary problems, but puts most of the blame for rising tuition on "the sheiks of OPEC" and fears that the quality of education will suffer unless a newly awakened faculty makes the major decisions. Spitzberg said that the profession may never be able to return to the button-down self-confidence and cardigan charisma of the past, although that "memory is lurking in the public conscious." Instead, he sees "the opportunity for an evolution."

One aspect of the evolution was apparent at a panel discussion on sexual harrassment -- the practice whereby a few unethical professors (usually male) obtain sexual favors (usually heterosexual) from students by the tacit or overt threat of academic reprisals. It's a tradition older than the ivy at most coed schools, but one that until recently has been "hidden," according to panelist Bernice Sandler of the Association of American Colleges. One recent study at Berkeley showed that 30 percent of female students had been accosted at least once.