NASHVILLE -- The hot, humid day had already turned into a hot, humid night and the home plate umpire had sweated through the light blue uniform shirt, revealing the straps of the chest protector. About 4,000 people were scattered through Greer Stadium to watch their Class AAA Nashville Sounds try to end a 12-game losing streak against the Indianapolis Indians, so the air was also thick with hope, as well as country music. Not much tension, though. Tension is rare for minor league baseball games in July.

The elderly couple sat behind and to the right of home plate, four rows up -- one row below the set of seats bearing Conway Twitty's name. The man's belly overflowed his belt, but his mind did not range quite as far. His wife seemed to be there only because he was.

"Hey," he said to her, along about the fifth inning, "the umpire's a woman. She walks like a man and she talks like a man. And she don't sound like Marilyn Monroe."

Indeed, Pam Postema does not sound like Marilyn Monroe nor look like her on this or any other night when she wears the tools of her trade, shin guards and a bulky chest-shoulder protector. But those are the tools of the trade for Postema, the only woman umpire in professional baseball.

The umpires' locker room at Greer Stadium is small, maybe 12 by 10 feet. One of those brownish-yellow bug tapes hangs from the ceiling. There are three locker stalls in the cinder block room, along with two showers, and a sink and toilet, which is separated by a door. The room has little charm and even less privacy.

Before and after games, Postema and her three male colleagues shower and change clothes in shifts. At some ballparks, there is no door separating sections, so they string up a makeshift curtain.

"It's been difficult, but we've made the best of the situation," said crew member Jack Oujo. "It would be a lot easier if all of us were men, but we've dealt with it well. And on the field, we just think of Pam as another umpire."

"The crew has had a very good year," said Oujo, who is in his third season at AAA. "At the beginning I questioned what kind of year we would have, but it's gone very well. To tell you the truth, Pam's gotten all this publicity, but the the three of us have had excellent seasons. Having three good partners reflects on the fourth person. We're a team and not four different individuals."

When Postema emerges for a game, she's wearing a uniform that is supposedly tailor-made, but still cut for a man. "It still doesn't look good," the 5-8, 135-pound Postema said with a smile. "I'll have to do my own shopping to get it to fit."

Her brown hair reaches her collar, but most of it goes under a cap. "What I am," she said sternly, "is another umpire, not a woman or a female. I've been in this for 11 years and I know that three-quarters of the fans don't know I'm a woman. They don't notice the umpire, anyway, unless something happens to bring the spotlight on them.

"I'm just trying to do my job. I don't think you have to think about being a male or a female. Whoever said it was only a male job just because only men have done it in the past?"

Postema does change her voice when she puts on her uniform. "It's a loud and aggressive voice," she says in her normal one.

Postema is not the first woman umpire in baseball, but she is the best, according to Barney Deary, administrator of the baseball umpires development program. With help from a court order, Bernice Gera was the first, but she lasted only through the first game of a New York-Penn League doubleheader in 1972. After an argument in the first game, she left the park in tears before the second game started. Christine Wrenn worked four seasons before taking a job in another field in 1979.

"I said she didn't have the talent," Deary said of Gera. "The court said she did and it took only one day to prove I was right. Wrenn was a possibility, but the wear and tear took its toll.

"Pam has handled the physical and mental wear and tear. She has not gotten run down and that's why she's the best female umpire we've ever had. But if you talk to Pam, she just wants to be considered an umpire and not a female umpire."

If she makes it to the big leagues, she would be the first woman to partake in a major league regular-season game. But being the first doesn't seem to be as important to Postema as just being there.

"She's just a very independent woman who believes that everybody should be allowed to do what they want to do," said Jeanelle Smith, who grew up near the Postema family in Willard, Ohio, and now lives in Phoenix, Postema's winter home. "But I don't think she's trying to set a standard -- it's a personal goal."

Said Postema, "I want the money, I want the career. You've put in a lot of time for nothing if you get this far and don't make it. What's the use of being in it if you're not in the best league? It applies in any profession. Who would want to be a secretary when you can be the company president?"

The idea of a major league manager bolting out of the dugout to berate a woman with four-letter words on national television doesn't particularly bother National League President A. Bartlett Giamatti, who, after 20 years as an English professor at Yale, should know a thing or two about language.

"I'm not quite in the business of enforcing public morality," Giamatti said. "I have always thought of baseball as a game of merit and skill. If someone has the talent and capabilities, they ought to have a chance to do it. If they don't, they don't. And my guess is that for as long as she's been at it, there aren't many forms of the English language she hasn't heard."

She is not without critics. Larry Bowa, who was managing Las Vegas of the Pacific Coast League last year, had a few harsh words after Postema ejected him from three games. This year, Oklahoma City Manager Toby Harrah suggested Postema was "out of her league" in the American Association, though later he said he probably had made the same comment about other umpires. When she was in the Class AA Texas League, somebody left a frying pan at home plate, though Oujo said that such silliness is rare by the time players and umpires get to the AAA level.

Indianapolis Manager Joe Sparks said he has "on occasion" disputed a few of Postema's calls, "but no more than with any other umpire."

As for whether he thought she was of major-league caliber, Sparks said, "I don't see why not. So many go from this league to the major leagues and I didn't think they were very good umpires.

"She realizes that she has to try to be better than any other umpire. The thing I like is that her calls are precise and quick. Whether or not she was right, she gives you the impression she thinks she's right. Some of them make calls and you can see they're not really sure."

But Deary said Postema can give it back, too.

"Oh, yes she can," Deary said. "Yes, she can. She's very, very strong. She's not bashful and shy. She's no Miss Milky Toast."

Deary said that like "99 percent of other young umpires," Postema made some ejections earlier in her career "that shouldn't have been ejections."

"I had to listen to everything, and I didn't want to miss anything," Postema said. "I always wanted the last word. But as you grow up and mature, you just concentrate on umpiring and don't worry about anything else."

Postema's Ohio high school didn't have organized sports for girls, so she played a variety of sports with her brothers and also on a women's fast-pitch softball team. After graduating in 1972, she moved around and worked several odd jobs: waitress, plumber ("actually we put in sewer and water lines"), bus driver, mobile home builder.

"No direction," Postema said with a laugh.

At one point, she was going to enroll at the University of Florida. While waitressing in Gainesville, Postema approached Al Sommers about entering his umpire school.

"I told her no," said Sommers, 82, who has since sold the school to National League umpire Harry Wendelstedt. "I told her that there's no future for a girl in baseball and that she'd be wasting her time and money. But she kept coming back and begged me to let her in." On her third try, Postema got in, enrolling at the school in January 1977.

"I didn't know what to expect, because I had never umpired before," Postema said. "It's one of those things where you don't know what to expect because you don't know anything about it. I thought it was something I'd like to try because I had always been athletic and loved baseball."

After graduating, Postema earned a job in the Gulf Coast League. Though he still isn't convinced she will ever make it to the big leagues because she is a woman, Sommers admires her for hanging in as long as she has. "She's showed 'em," Sommers said.

Her parents "think that it's really neat and they're happy for me," Postema said. "As long as I'm happy, they're happy. I don't think they thought it would last this long. But they are very proud of me."

Said Smith, "Pam's always been a unique person and I always knew she would end up in a field that was challenging and different."

An umpire's nomadic life is certainly different. Unlike players, who play half their games in one place, even if it isn't home, umpires are constantly on the road. Postema travels with a trunk that holds her equipment, a suitcase and a carry-on bag. Like other umpires, her mail is sent ahead to whichever city she goes to next.

"That drives me crazy," she said. "Bills are due all the time. You have to find out how much they are, have them sent to you and you can't get to your own bank. That's the only thing bad about traveling, but you're always carrying receipts. I swear I have receipts everywhere -- pockets, suitcases, everywhere."

Ed Vargo, the National League supervisor of umpires, said he wouldn't want his daughter to be an umpire. "It takes a certain breed to be an umpire and my daughter isn't that breed -- she's going to be a school teacher," Vargo said. "You have to be devoted to the game and really love it. You're away from family and traveling constantly. There's also a lot of abuse. When you put the blue uniform on, you're wrong from the start. It's the only profession I know of where you're supposed to be perfect on opening day and then improve."

The travel also means a personal strain.

"Sure," Postema said. "There were relationships I moved away from because I had to go to spring training here and there, and I've gone a couple different places during the winter. And I've worked in different leagues around the country. But basically I think I still wouldn't be married. Well, maybe not. But I'm not much for the institution of marriage, anyway."

An avid exerciser and shopper, Postema "kills time" before games by playing tourist, or looking for a local YWCA or a great bargain. But minor-league umpires don't make a lot of money. Postema said she thought she was one of the highest paid umpires in Class AAA at $900 a month, with a $55 per diem.

"During the season, I spend it mostly on hotels," Postema said, "But I do like to shop and what else is there besides jewelry, makeup and clothes? I've only sent two boxes home this year, though.

"This hotel costs $40 per day, which leaves $15. But then we give the clubby {clubhouse man} five or six bucks a day. Then I usually try to eat a couple of times a day. It's tough."

After a game, she will sometimes join the other three crew members for a beer and hamburger. But socializing with players is not done.

Postema, 33, is in her 11th minor league season. It would seem that Postema's best chance of advancing to the majors is in the National League because its officials have been a bit more enthusiastic in their assessments of her and because the league may have a couple openings next season. Marty Springstead, supervisor of umpires for the American League, said he doubted his league would have an opening during the next few years.

It was the National League's turn to pick the umpires for the July 27 Hall of Fame exhibition game in Cooperstown, and Postema was given the plate. National League officials are quick to say that the game assignment had more to do with Postema's crew working in Buffalo than with any plans to bring her to the majors.

"It was more practical," Giamatti said. "But it gave Ed Vargo and me a chance to see her work in major league conditions. I had a positive impression. She did a good job."

Postema considered it an honor. "Definitely one of the highlights of my so-called career. The ambiance of the town is pure baseball," she said. "But it doesn't mean I'm in the big leagues."

She has umpired in the Gulf Coast League (Rookie), Florida State League (A), Texas League (AA), Pacific Coast League and American Association (AAA). After having toiled in places like Midland, Tex., and Omaha, it would be a major disappointment not to make the final step to places like New York and Los Angeles.

"You would've put in a lot of time for nothing," said Postema, who adds, "Yeah, I think I will {make the majors}, but what I think doesn't matter. What I think and a quarter will get you a cup of coffee."

If there are baseball people who want to maintain this bastion of masculinity, they haven't spoken to Deary.

"They've never said anything directly to me, but I've heard stories and rumors," he said. "My friends and neighbors think I'm crazy, though. But I tell them that we have women driving 18-wheelers and women flying airplanes. I don't hesitate to get on a plane with a woman pilot.

"Let me ask a question. If there was a woman in Triple AAA hitting 50 home runs a year, do you think she'd play in the majors? Damn right she would. Whether there is a woman who can hit 50 home runs, I don't know. We haven't found one yet. But we have found a woman that can umpire."