Sound recording and reproduction 1920s when several radio-related developments in electronics converged to revolutionize the recording process. These included improved microphones and auxiliary devices such as electronic filters, all dependent on electronic amplification to be of practical use in recording. In 1906, Lee De Forest invented the Audion triode vacuum tube, an electronic valve that could amplify weak electrical signals. By 1915, it was in use in long-distance telephone circuits that made conversations between New York and San Francisco practical. Refined versions of this tube were the basis of all electronic sound systems until the commercial introduction of the first transistor-based audio devices in
Anil K. Jain (electrical engineer, born 1946) Anil K. Jain (electrical engineer, born 1946) Anil K. Jain (January 21, 1946 – November 14, 1988) was an Indian-American electrical engineer and Professor of the Department of Electrical Engineering and Computer Science at the University of California, Davis, known for his contributions on "two-dimensional stochastic models for images provided a firm theoretical foundation for a number of algorithms of spectral analysis, adaptive image estimation and image data compression", including work on transform coding for image compression and block-based motion compensation for video compression in particular. Born in India, Jain received a bachelor's degree in electrical engineering in 1967 at