(CNN) -- Tubes used to clear his lungs prevent Nelson Mandela from speaking, and he uses facial expressions to communicate with doctors and family, according to his former wife.
"He remains very sensitive to any germs, so he has to be kept literally sterile," Winnie Madikizela-Mandela told South Africa's Sunday Independent newspaper in an article published Sunday. "The bedroom there [at his home] is like an ICU ward."
Mandela, 95, "remains quite ill," she said, but doctors are tending to his needs at his residence in Houghton, a suburb of Johannesburg.
The tubes are used to prevent infection in Mandela, who is said to be stable.
"He communicates with the face, you see," Madikizela-Mandela told the newspaper. "But the doctors have told us they hope to recover his voice."
On September 1, the renowned leader was discharged from a Pretoria hospital where he had been receiving treatment since June, the South African president's office said Sunday.
Mandela was hospitalized June 8 because of a lung infection.
The frail icon has not appeared in public for years, but he retains his popularity as the father of democracy and emblem of the nation's fight against apartheid.
Mandela became an international figure while enduring 27 years in prison for fighting against apartheid, the country's system of racial segregation. He became the nation's first black president in 1994, four years after he was freed from prison.
His history of lung problems dates to his imprisonment on Robben Island, and he has battled respiratory infections since then.
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