Digital (London: Wallflower Press 2005) Eyman, Scott. The Speed of Sound: Hollywood and the Talkie Revolution 1926–1930 (New York: Simon & Schuster, 1997) Gomery, Douglas. The Coming of Sound (London & New York: Routledge, 2005) External links List of Early Sound Films 1894–1929 at Silent Era website Alfred Hitchcock and Anny Ondra in Sound Test for Blackmail (1929) filmed in RCA Photophone J.R. Sky, as the successor to Nuoptix, which, in turn, was the successor to Litton Industries' Westrex subsidiary History of film Film sound production Film and video technology Motion picture film formats RCA brands Academy Award for Technical Achievement winners