From Empire Magazine:

“It was quite an unusual situation,” Serkis tells us in the new issue of Empire. “I worked specifically with Domhnall Gleeson and with Adam Driver. My first day was basically standing on a 25-foot podium doing Lord Snoke without the faintest idea what he looked like… or in fact who he was! I was very high up, totally on my own, away from everybody else, but acting with them.”

“He is severely damaged. Although he’s a powerful leader, he comes across as vulnerable. Very scarred and disfigured.” But the actor assures us that Snoke is a guaranteed force to be reckoned with: “we used sort of a ‘Kongolizer’ method of having sound come out of speakers to give a sense of scale and distance for the character. So it was very challenging and scary, in fact probably one of my most scary film experiences I’ve ever had.”