Or so they claim. From the BBC:
In 1969, a mysterious middle-aged Latvian doctor turned up in Gerrards Cross with a large collection of tape recordings.
He had, he said, been conducting experiments in communication with the dead, and had established contact with Hitler, Stalin, Mussolini and many other deceased 20th Century statesmen. The recordings - 72,000 of them - contained their voices.
His name was Konstantin Raudive, and he called his technique Electronic Voice Projection, or EVP.
It wasn't real-time interactive communication. You asked your questions, and then left the tape running, recording silence.
But listening back, through the mush and static, you could sometimes just about make out people speaking.
Gerrards Cross was the home of a publisher, Colin Smythe, whom Raudive hoped would publish a book on his findings.