Being in the proximity of Tracey Ullman can be an intimidating experience.

It's not that she's not lovely and funny and charming. She is. But it's hard to shake the feeling that she's sizing you up for future characters she'll use in her comedy."Oh, they're all people I know," Ullman told TV critics. "I observe you all. I love it. I mean, some actors and actresses dread these sort of junkets. . . . I love it because I just use it to listen to the voices."

And what she does is she takes those voices and creates entire characters. It's a talent that she's displaying once again in her new HBO series "Tracey Takes On . . .," which debuts tonight at 11:30 p.m.

"It's always the voice. The voice comes first," Ullman said.

And doing voices is something that came naturally.

"As I child I could imitate everybody," she said. Among her early influences were British films she calls "working class dramas."

"I didn't ever want to be the pretty girl. I wanted to be the person with the problem," Ullman said. "I remember there was a play called `Edna the Inebriated Woman,' all about a homeless woman shouting at people. . . . And I wanted to be Edna. . . . And my mom's like, `Why can't she want to be Cinderella?'

"And I just used to sit in front of mirrors, smoking cigarettes, just talking like welfare wives for hours. And my mom would knock on the door and say, `Oh, shut up!' "

These days, Ullman uses more than just her voice to become someone else.

"I have these wonderful people that help me with the costumes and the prosthetic makeup that I wear," she said.

Sometimes that makeup can be extensive. Ullman takes on the personna of characters of widely different ages, different ethnic origins, even different sexes in the course of a half-hour program.

"The makeup is tough. I mean, Mrs. Noh Nang Ning, the donut shop owner, oh!" she exclaimed. "It was like being buried alive."

That character, like almost all of the others, will be new to American audiences who know Ullman only from her Emmy-winning Fox series "The Tracey Ullman Show."

"Only Kay, my little spinster from England, transferred because I own that character," she said. "All the other characters are owned by Fox, so I had to sort of re-create them."

Hard to believe as it might be, Ullman insists that characters like Kay, Mrs. Noh Nang Ning and a male, Mideastern cab driver genuinely are based on real-life people. Odder still, she says none of them has ever figured that out.

Mrs. Noh Nang Ning was someone who, "when we were writing the show, we would go and buy donuts," Ullman said. "And I'd just sit and get a cup of coffee and watch her."

Then there's dear Kay.

"I love Kay. I'm very fond of her," Ullman said. "This little British spinster - she's so courageous, and to think she's sort of on national television in America is rather thrilling to me when I used to witness her in the local bank in my village.

"She'd say, `Hello, Miss Ullman. How's Hollywood?' And to think she's on American television and - she doesn't know!"

But people far closer to Ullman have never figured it out, either.

"I've impersonated my best friend on a show in England for like five years. . . . And when I did this character every week on television, she used to say, `She's such a tch, that girl!' " Ullman said. "And she never got it. Everyone was amazed. She never got it. It was weird."

Speaking of weird, wait until you see Ullman as a male cab driver.

"I decided to do the Middle-Eastern cab driver because I just keep getting in that guy's cab in New York," she said. "He kept driving me around at 90 miles an hour."

Of course, this character also required a lot of makeup.

"I just covered myself with hair . . . and it was very disturbing for my 4-year-old son to show up on the set," Ullman said.

"It is very strange for him. It is. And when I was this hairy man, when I came home at the end of the night, it's like - `You're Mommy again? You're not going to do anything funny?'

The sketches on "Tracey" run the gamut from comedy to pathos to social commentary. The restrictions of playing the same character in a weekly sitcom aren't for Ullman.

"I just like doing so many different characters. I really do," she said. "I'm too old to be in `Friends.' I'm 36 years old, you know. I'd be the one moaning about the approach to menopause.

"I like this multicharacter stuff. My heroes are Peter Sellers, Gilda Radner, Carol Burnett."

Ullman did say that none of her characters has come directly from members of the media - at least "not so far."

" `Tracey Takes On the Press" would be a good one for next year," she said.

MOTHER AND DAUGHTER: Fans of the old "Tracey Ullman Show" may recall that Ullman used to talk about her baby, Mabel.

Well, that baby is almost 10 now, and she's giving her mother a bit of a hard time.

"Mabel's extraordinary," Ullman said. "I mustn't talk about her anymore, though. I mean, because I think she's going to be on one of the show's with Kathie Lee Gif-ford's son. When she's like 18 - kids-whose-famous-moms-talked-about-them-too-much-on-TV."

Mabel, however, doesn't aspire to follow in her mother's footsteps.

"People still say, `Do you want to be an actress?' " Ullman said. "And she says, `No, I want to be something useful like a nurse.' She's very disparaging about what I do."

She's also at least a bit embarrassed about having a famous mother. Ullman recounted a recent incident when she volunteered to accompany Mabel's class on a field trip.

"She said, `Oh good.' And she said, `But Mommy, I know it makes you happy but please don't do your voices,' " Ullman said with a laugh. "It's like, oh please, I'm this embarrassing mother on the bus.

"And if I take her and her friend out I have to sit at another table. And they just giggle about me.

"And if I wear, like, jeans to her school she goes, `Dressing like a 16-year-old, Mommy?' Ah, she's amazing."