The Sound Barrier (known in the United States, as Breaking Through the Sound Barrier and Breaking the Sound Barrier) is a British 1952 film directed by David Lean. It is a fictional story about attempts by aircraft designers and test pilots to break the sound barrier. It was David Lean's third and final film with his wife Ann Todd, but it his first for Alexander Korda's London Films following the break-up of Cineguild. The Sound Barrier stars Ralph Richardson, Ann Todd, and Nigel Patrick. The Sound Barrier was a box-office success on first release, but it has become one of the least-known of Lean's films. Following on In Which We Serve (1942), the film is another of Lean's ventures into a genre of filmmaking where impressions of documentary film are created.[3]