Michael Schumacher, the seven-time Formula One racing champion, who suffered massive head injuries in a skiing accident in December 2013, is responding to external stimuli, but is unable to speak or move, according to reports.

Schumacher, who left hospital to return to his home in Switzerland after nine months of treatment, spends much of his time "looking into the void," according to a report in Autosprint magazine, cited by the Times of London

Alberto Sabbatini, Autosprint's editor, told the paper that “sometimes a tear rolls down Michael’s face. He cries when he hears the voice of his children or [his wife] Corinna.”

Sabbatini added, however, that the racing star is still unable to communicate meaningfully with his family: “It shows that he feels emotion; that his brain works. It is the only way his strong character is able to externally convey an emotion,” he said, according to the Times.

Sabbatini claimed that Autosprint's information was collected "as objectively as possible," based on "reliable and verified information" from "those who know and have seen him recently and are aware of his clinical status," according to Motorsport.com

Schumacher sustained a traumatic brain injury in Dec. 2013, after hitting his head on a rock while skiing off-piste in the French resort of Meribel. His family and management have remained tight-lipped about the athlete's medical status since the accident.

In November, Philippe Streiff, supposedly a friend of Schumacher's and a former racing driver, claimed that he was confined to a wheelchair and unable to speak.

Schumacher family spokesperson Sabine Kehm said at the time that Schumacher's recovery would “need a long time -- it's going to be a long time and a hard fight." "He is making progress appropriate to the severity of the situation. I cannot confirm that [report]. I can only confirm that I do not know where Mr Streiff has his information from because he has no contact with us and he never has," Kehm told Reuters.