Blackmail (1929)

Hitchcock is another classic suspense thriller, which tells the story of the heroine being blackmailed after defending himself. In the later stage of filming, the boss asked Hitchcock to change it into a sound film. Hitchcock remade part of the scene to add sound, so the film became the first British audio film, so most cinemas had no audio equipment, so it was shown in both silent and audio versions. Over the years, audio-visual products are common in audio-visual version, but in fact, the silent film version is more successful, and it has a unique skill in how to deal with voiceover.