 In 1952, three researchers at Bell Labs, Stephen.Balashek, R. Biddulph, and K. H. Davis, developed a system that could recognize digits spoken by a single speaker.Linear predictive coding (LPC), a speech processing algorithm, was first proposed by Fumitada Itakura of Nagoya University and Shuzo Saito of Nippon Telegraph and Telephone (NTT) in 1966.