The 39-year-old Brazilian, who has started more races than any driver in the history of the sport, suggested on Thursday that some of the speculation about possible replacements was wide of the mark in any case.
"There are a lot of talks. I believe they (Williams) are talking the truth to me, and the truth is that the rumours are much bigger than the reality," he told reporters at the Abu Dhabi Grand Prix. "I just have to wait and believe, and when I have conversations to look in the eye of people, I believe they seem to be saying the right things for me."
Former champion Kimi Raikkonen has appeared on the radar as a potential rival for Barrichello\'s seat.
Raikkonen has been in the headlines after Williams shareholder Christian 'Toto' Wolff was quoted this week as saying the 2007 world champion, who left the sport at the end of 2009, was under consideration for a comeback.
Williams have made no comment and Raikkonen, famously taciturn in his time in Formula One, has been vague.
"To be honest, I never talk to Kimi. Even when he was racing he never talked to me," smiled Barrichello, who negotiates for himself, when asked what he knew about the situation. "I believe that he had very little talks with the team, by any means."
"I can't talk anything bad about Kimi, I can't talk bad about anybody. I think all are in contention, I just hope I'm the better option," said the Brazilian, who described his position as "calling and just waiting for people to call."
Germany's Adrian Sutil, waiting for Force India to decide whether to retain him, has also been held up as a strong candidate.
Barrichello recognised he could go into the final race of the season, his home Brazilian Grand Prix, this month not knowing whether it would be his last.
"I'm not saying goodbye to my fans. I want to be there next year, taking the risks," he said. "I just have to wait and see...I'm very motivated, I'm waiting for an answer and, if God wishes, I will be on the grid for my 20th year (in F1)."
Barrichello, winner of 11 races with Ferrari and Brawn, said he had been talking to other 'competitive' teams and was concentrating on the positives.
"If I was in my first or second year then I'd be very worried, but it's been such a long time, and life is too good to be moaning about problems and why they haven't signed me just yet," he said of Williams.
Sutil was unable to shed any light on his future. "I don't think after so many years doing a good job in this team I have to shiver and think about my future or something, I am relaxed," he told reporters. "I like this team but if it doesn't work out, then I'll find something else.
Asked whether he might benefit from a change after five seasons with the same team, the 28-year-old, who faces competition for the seat from reserve driver and compatriot Nico Hulkenberg, added: "I am open for every change, absolutely."
"But I want to be sure that it is the right way to go, I don't want to change a team if I don't want to. But I think in a driver's career of course, to change teams and be with different teams I think is necessary."