Redmayne spent six months researching Hawking's life, watching every piece of interview footage he could find of him. He studied Hawking's accent and speech patterns under dialect coach Julia Wilson-Dickson to prepare for the role. Marsh stated that what Redmayne had to do was not easy. "He had to take on enormous amounts of difficult preparation, as well as embracing the difficult physicality of the role. It's not just doing a disability. It's actually charting the course of an illness that erodes the body, and the mind has to project out from that erosion", he said. He added that Hawking gave him his blessing, and also revealed that, "[Hawking's] response was very positive, so much so that he offered to lend his voice, the real voice that he uses. The voice you hear in the latter part of the story is in fact Stephen's actual electronic voice as he uses it", he said. It was revealed to the Toronto International Film Festival (TIFF) audience that as the lights came up at a recent screening, a nurse had wiped a tear from Hawking's cheek.
