Early last year, HaUyen Pham, who was nine-months pregnant with her daughter at the time, was put in an odd situation.

A courtroom audience roared as a litany of vulgarities poured from her mouth.

The judge turned red and asked Pham to temper her words.

"I just said, 'Judge, I was just doing my job,'" she recalls.

Her job? Court interpreter, and in this case, she was translating for a homeless man - a regular at the Dorchester District Court - who had been brought in over a charge of indecent exposure and wasn't taking well to it.

The incident is an illustration of one of those rare moments for a court interpreter.

"We're in the middle of everything but at the same time we're supposed to be invisible," says Pham, who is originally from Saigon, Vietnam.

The job is rewarding, but demanding, she says. Pham got into the job ten years ago after graduating from college and meeting a friend who was a Spanish interpreter.

Demand is growing for interpreters such as Pham, as Dorchester grows more diverse.

"They're in high demand," says Dianna Abdala, a defense attorney, after finishing up an assault and battery case on Tuesday where Pham translated for a husband and wife. "Especially in this area."

Without them, it would be impossible for her to communicate with some of her clients and their family members, Abdala says. In the case Pham had just translated, she had helped the client understand his constitutional rights and when he pled guilty, she helped to explain the stage his case was at, Abdala said.

Because of the range of languages needed, Dorchester District Court is reportedly among the top-spending courthouses when it comes to interpreter services. (Courts are required to have interpreters, if needed, at all stages of a court proceeding.)

Interpreters can be present from simple traffic violations to capital murder cases, along with assisting office attorneys, mental health hospitals, depositions, or going to prisons to help with interviews.

The languages include Spanish, French Creole, Cape Verdean, and Vietnamese as some of the most frequently used, but also include Polish, Cantonese and Mandarin Chinese, Somali, Russian and French.

Judge Sydney Hanlon, who heads the Dorchester courthouse, often tries to ask people if they are comfortable speaking in English as they approach her bench. While some will seem comfortable filling out a form, the situation can change when they are thrust into an unfamiliar setting such as a courtroom with its own special terminology, she says.

It's a delicate balance, says Hanlon, who learned French in school and knows some Spanish. "You don't want to be disrespectful," she says. "By the same token, you want to make sure they understand."

All seem to agree on another aspect of the interpreter's job: There aren't enough of them.

According to the Office of Court Interpreter Services, which manages and certifies interpreters, there are 175 interpreters in 35 languages for the state's 140 court divisions, including district, juvenile, housing, probate, family and superior courts.

There are about 59 Spanish interpreters, with 14 for Portuguese, five for Haitian Creole, seven for Chinese, eight for Vietnamese, and five each for Russian and Polish, according to the OCIS's website.

A number of them are freelancers, who crisscross the state, with some doing three courts a day, if necessary. They can get paid around $300 a day and receive a per diem to cover travel costs. Mondays are the most hectic, with arrests and restraining orders having accumulated over the weekend.

"We go wherever they send us," says Tania West, a Spanish interpreter from Nicaragua who covers mainly the North Shore and was in Dorchester this week for the first time in about a year. "Lynn is a pretty hectic court."

Artemisa Monteiro, a freelance Portuguese and Cape Verdean interpreter, has had to go from Springfield to Martha's Vineyard at one point, and has been out as far as Barnstable, Chicopee and East Hampton.

That was before budget cuts. Now, they try to keep her assignments in the same county, she says, and she mostly travels to Malden, Somerville, Cambridge, Quincy and Dedham.

Up until three months ago, she traveled mainly by the T. A Dorchester resident, she is a Cape Verdean who had studied at a Portuguese boarding school. A former pre-school teacher, she decided to become a stay-at-home mother, until her mother came over from Portugal in 1997 and pressed her to go back to work.

That same week, her ex-husband was in court and saw an interpreter at work. "In his head, it was like, my wife can do this," says Monteiro, who plans to attend law school next year.

Monteiro is one of five Cape Verdean translators for the entire state's trial court system.

"Sometimes, the need is so great, they just use anybody" from the audience, she says. Not everyone who is bilingual can be an interpreter, she says, and most foreigners with credentials are in other professional fields, she adds. Interpreters must also have an outgoing personality and patience, she said.

Along with keeping a straight face in court, interpreters must also remain neutral in the cases they translate. Pham recalled another case, one of her first, which involved a man accused of raping his step-daughter. It hit her hard, she said: The victim had the same first name as she did. Afterwards, Pham said she had to run out of the courthouse.

The shortage of interpreters sometimes causes court staff to get called in and asked to help out, particularly with cases involving French Creole or Spanish speakers.

That can be controversial, Judge Hanlon acknowledges. But she also notes that people have jobs to go to after court and have difficulty coming back another day when an interpreter is available.

"Rather than make them take another day from work, we'd rather do that," she said.

It also causes arguments from some lawyers that language barriers exist to be greeted with some skepticism. This past Monday, local attorney Leon Drysdale told Judge Rosalind Miller that it was "counterproductive" to hold his client, who owed a significant amount of money to the court, in custody.

Miller noted that his client had not made an effort to attempt community service.

Drysdale pointed to a "language situation."

"Not in this court," Miller snapped back.