Natalia Rom usually spends her days scrubbing toilets and tables at a suburban McDonald's, while her husband Alexander works in an All American Jeans warehouse.

Last week, the 28-year-old Russian Immigrant was in New York City and hoping for a new job, but she didn't go to any hamburger stands.She was at the Metropolitan Opera, learning from-and singing with-some of the best teachers and vocalists in the country.

Rom wasn't uninvited; she belonged there because she was one of 23 regional winners in the Met's annual auditions program. The week of hard work paid off Sunday when she was named one of 11 winners of the competition. Rom and 10 others will get $3,000 and will sing arias in a nationwide radio broadcast from the Met stage next Sunday.

In other years, top winners were named, and sometimes a one-year Met contract was awarded. But because of a state law forbidding age discrimination if there is a possibility of employment, top prize winners will not be named this year.

During Sunday's 5 1/2 hour competition, she sat backstage in a waiting room with her rivals, wringing her hands as their performances were piped in on a speaker. She was nervous, she says, "because the judges told me that it was the highest level of competition they had seen in years."

When she was named a winner, she said, she began to cry "because I didn't expect it. I don't know how I felt, though. I just knew that I was very tired."

Whether the publicity from the experience will be enough to land her an operatic job-not necessarily at the Met, but someplace where she can devote her energy to singing instead of scrubbing-is an open question. After all, Rom has been studying voice only 18 months.

Although she says operatic singing always has been a dream of hers, Rom studied choral conducting at the Leningrad Conservatory, where she and her husband met and earned master's degrees in the subject.

In 1975, the Roms felt anti-Semitic pressure in the Soviet Union was increasing when three Jewish fellow conservatory students were photographed by the Soviet secret police (the KGB) when they attended Yom Kippur services.

"We saw we had no future there," Alexander Rom recalls. "I told my wife, 'We have to run away.'"

After what Natalia Rom calls "almost two years that seemed like five," the family gained entry to the United States - but not all at the same time.

First came Alexander Rom's sister, who, he says, made "noise" over Radio Free Europe about the family's plight. Then came Rom's parents and grandparents and, finally, near the end of 1976, the couple and their infant son, Albert, now 3. Natalia Rom's parents are still in her hometown of Perm. She says, "They didn't like the idea of my leaving."

HIAS, a Jewish refugee service, picked New Orleans as the family's new home and referred the new arrivals to Lola Bernstein, who served as a volunteer interpreter-no one in the family spoke any English. She also became their fulltime guardian angel.

When Bernstein learned of the couple's musical gifts, she took them to Larry Wyatt, Loyola University's choral director, for paying jobs as singers in a New Orleans church choir. At the church, Patricia Brooks Etienne, a Loyola voice teacher, noticed Natalia Rom's rich, powerful soprano and offered her free singing lessons.

Recalls Etienne: "When I suggested she take lessons, she said, 'Do you think I can sing?' and I said, 'Yes, you certainly can sing.' She's a good student because she assimilates everything you tell her when you tell her."

After a few months of study, Natalia Rom entered the local Metropolitan Opera auditions last year. The judges commended her on her Italian arias but said her Russian pronounciation was bad.

"They said I couldn't move enough on the stage," Rom says, wringing her hands. "That my voice wasn't strong enough for opera. They said my into nation was bad.I knew that last part was nonsense because intonation was part of my education as a choral director, but I really was very depressed after that audition. I was killed. I didn't want to sing at all."

"It was my effort and Mrs. Etienne's to get her to sing again," says Alexander Rom, 26, of his wife of six years. "I gave her no choice. For three months, she didn't open her mouth."

She resumed her lessons and, with money from the Council of Jewish Women, enrolled at Loyola. She signed up for this year's local Met auditions but, she admits, "I had no hope. I was ready to do it for the experience, and my husband had promised to buy me ice cream if I did well, so I though about ice cream. I wasn't even listening when they announced the winners."

Her husband was listening and, he says, "When she won, I made a noise like a lion in a cage. I had to push her on stage. After that, she got ice cream."

At the regional level of competition, Alexander again accompanied her.

"I was scared I would forget the words," Natalia Rom says. But Alexander refused to let her listen to her 11 rivals and promised her ice cream again.With that on her mind, she sang and won. CAPTION: Picture, Natalia Rom, by Mark Petty