"She said I had plateaued, and that I was as good as I was ever going to be," recalls Ms. Hervey. That prognosis, says Ms. Hervey, was wrong. Her stroke was 13 years ago, and she has persevered, continuing to improve her speech through other therapy ever since. She found a center in New Jersey that would work with her long-term, and she regularly rides a bus three hours each way between the center and her home in Stewart Manor, N.Y.

Today, Ms. Hervey, a 62-year-old retired lactation consultant, can recount the entire episode herself, clearly, in her own words.

Ms. Hervey's experience is a common one among people suffering from "aphasia" -- the inability to speak or sometimes even read, write or understand speech that can be a side effect of stroke or other brain injury. Many patients are told that if their speech doesn't return after a few months or a year of therapy, they will never recover. Insurance coverage for therapy, which can cost $65 to $150 for a one-hour session, typically runs out after a few months.

For the more than one million people in the U.S. estimated to be hampered by aphasia, the negative prognosis can be a self-fulfilling prophecy, and many patients stagnate. But a handful of stroke experts, speech therapists and patient advocates say that patients should hold out hope. Increasingly, anecdotal evidence suggests that aphasia patients who persevere with therapy for the long haul -- beyond a year -- can still recover meaningful speech.

"There's no set limit as to when someone will recover," says Anna M. Barrett, a stroke neurologist and director of stroke rehabilitation research at Kessler Medical Rehabilitation Research & Education Corp. in West Orange, N.J. She estimates that "most people get about six months [of speech therapy], and maybe about a third get up to a year," but that in her experience, individuals can improve even years after a stroke.

Of course, long-term therapy isn't a magic bullet, and there are no guarantees that patients will recover their speech. Patients may spend years of grueling, costly therapy and still not recover meaningful speech. Insurers say there are medical and financial reasons to discontinue speech-therapy benefits. A spokesman for Blue Cross Blue Shield of Illinois notes that there is no clear end point for success with therapy.

Dr. Barrett, who is also an associate professor of physical medicine and rehabilitation at the University of Medicine and Dentistry of New Jersey, says doctors measure progress at certain milestones, such as six months or a year and sometimes regard lack of progress as a final prognosis.

Sandy Simon, a Florida businessman and former stroke patient who gives speeches to current stroke patients, says he often asks audience members how many were told they would have to recover within a few months of their strokes -- or not at all. "They all raise their hands," says Mr. Simon, who says he encourages patients he meets to persist with therapy.

The benefits of longer-term therapy haven't been systematically studied. But some advocates point to medical science's growing understanding of "neuroplasticity," the ability of brain cells to change and adapt. It was once thought that we lose neuroplasticity after we reach adulthood. But neurologists increasingly believe it can continue throughout life, offering hope to stroke patients and others with brain injuries that healthy cells can learn the function of damaged adjacent cells -- such as those that control speech.

At the forefront of the nascent movement for longer-term therapy is the Adler Aphasia Center in Maywood, N.J., where Ms. Hervey is a client. Many patients "are told they won't improve and that their insurance is cut off," says Karen Tucker, executive director of the center. "They've been given a very negative prognosis."

The Adler center offers speech therapy to about 85 people at the rate of $15 a week. The therapists, who are all licensed speech therapists, describe the center's methods as a "life-participation approach," which focuses on group discussions, rather than individual sessions, as with most speech therapy.

The low rates at the center, which doesn't accept insurance, are subsidized by Michael and Elaine Adler. Mr. Adler, a wealthy manufacturer of personalized pens and calendars, suffered a stroke 13 years ago and became aphasic. "I couldn't talk, and I was ashamed to talk," he says now. He went to five different speech therapists, in many cases repeating words over and over in what to him was a stunningly boring process. Finally, the last of the therapists helped him get over the embarrassment that he says is a central factor impeding aphasia patients' improvement. Now he speaks well, though sometimes haltingly as he searches for words.

The Adler center has the homey feel of a large living room. There are sofas, lounge chairs, a dining-room table and kitchen, and a table with jigsaw puzzles. Much of the speech therapy is tailored to the interests of the members. For instance, Ken Albrecht, a borough councilman in Haworth, N.J., who had a stroke in March 2005, worked with a computer program to help him shape sentences about public policy and politics. He was able to speak publicly before the November elections, and was re-elected.

Speech disabilities take numerous forms, including difficulty summoning words, physical difficulty in uttering them and limits on understanding others' speech. Many of the patients -- though they're always called "members" to stress this is a nonmedical setting -- have experienced speech therapy elsewhere. Often, as in Mr. Adler's case, they were urged to repeat a single word over and over. Several say they've become far more motivated to talk by the approach used at the Adler center.

Group discussions predominate. One recent group focused on Sen. Barack Obama, of Illinois. The six participants talked about his background and the likelihood of his pursuing the Democratic nomination for president in 2008. The conversation was animated, though some of the people involved clearly struggled to get words out. They were all determined to jump in.

Clients work in teams at computers, using software such as Sentence Shaper, Parrot and Bungalow. Some involve matching words with pictures that help them in shaping sentences. Advanced students work on recording words in their own speech and shaping sentences with them that will be of use in their lives, whether they be artists, doctors or politicians. "We have our members making up dictionaries that are relevant to them," says Chrysa Golashesky, a computer coach.

The Adler center is one of a handful that heavily employ the group, or life-participation, approach. Ms. Tucker, the executive director, points to the Aphasia Institute in Toronto, the Aphasia Center of California in Oakland, and a center called Connect in London. The Adler center is currently accepting new members.

Oscar Ravina, 76, attends the Adler center regularly with his wife, Ruth. Mr. Ravina for 40 years was a violinist with the New York Philharmonic. The morning of May 15, 2003, he couldn't turn off his alarm clock. His arms started flailing and he fell to the floor. It turned out to be an acute stroke, caused by a blood clot, that rendered him totally speechless.

"The doctors told us that after a year, there wasn't likely to be a lot of improvement," says Mrs. Ravina. But as with Ms. Hervey, this prognosis proved wrong. A speech therapist working with him about a year after the stroke discovered that he responded to instruction related to music. She brought in catalogs of musical instruments for him to discuss. His speech began to take off. But it was at this point that his insurance no longer would pay the $130 cost of hourly sessions.

So he started at the Adler center and continued to progress. Now, while his speech isn't always understandable, he is willing to make telephone calls, order food in a restaurant and chat with friends when they visit. He still speaks haltingly, and some words can sound garbled.

Still, his progress has allowed Mr. Ravina to resume teaching violin. "I'm very grateful for what I can possibly do right now," he says.

Write to Thomas M. Burton at tom.burton@wsj.com