Cohen, 41, is working with vocal coaches in Hollywood in a bid to copy the former Queen frontman, reported Sun online.
He has also pored over hours of Queen concert footage and private videos of Freddie in reflective and sombre mood.
"Sacha is a huge Queen fan and is focused on getting Freddie's mannerisms, style and speech perfect. He is working on building his vocals. It is a uphill task, because Freddie has such a unique power and tone," a source said.