Lalit R. Bahl

Timeline

1. 1964–1969

   Degrees from Kharagpur and Illinois

   He earns a B.Tech at the Indian Institute of Technology Kharagpur in 1964, then an MS in 1966 and a PhD in 1969 in electrical engineering at the University of Illinois at Urbana-Champaign. The Indian Institute of Technology gives him its President's Gold Medal for Outstanding Graduate of the Year in 1964.

2. 1968–1972

   IBM's Speech Recognition Group

   He joins IBM's Thomas J. Watson Research Center in 1968 and works on projects in information and communication theory. In 1972, he moves to the newly formed Speech Recognition Group, where he and two colleagues apply Markov models to speech recognition.

3. 1974

   The BCJR decoding algorithm

   In 1974, he introduces the BCJR algorithm with John Cocke, Frederick Jelinek and Josef Raviv, named from their surnames. It performs maximum a posteriori decoding of error correcting codes defined on trellises.

4. 1979–1997

   Managing IBM's Speech Algorithms Group

   From 1979 to 1997, he manages IBM's Speech Algorithms Group, and virtually every speech recognition research and development team in the world adopts the methods and algorithms he and his colleagues originate. IBM's ViaVoice and Simply Speaking systems, which let PC users create documents by speech, use these techniques. In 1991–92, he leads a team at the IBM Science Center in Paris that develops a multinational speech recognition system.

5. March 1983

   Maximum likelihood speech recognition

   In March 1983, he publishes "A Maximum Likelihood Approach to Continuous Speech Recognition" with Frederick Jelinek and Robert L. Mercer in IEEE Transactions on Pattern Analysis and Machine Intelligence.

6. 1997–2012

   Two Illinois alumni awards

   The Electrical and Computer Engineering department at Illinois gives him its Distinguished Alumni Award in 1997 for contributions to speech recognition and information theory. In 2012, he receives the Alumni Award for Distinguished Service from the University of Illinois College of Engineering.

7. 1998

   Joining Renaissance Technologies

   After retiring from IBM in 1998, he joins the hedge fund management company Renaissance Technologies as a senior research scientist. There he applies statistical modeling and inference to the analysis of the stock market and the automated execution of trades.

8. August 2025

   Death at 82 in East Setauket

   He dies in August 2025 at age 82, at his home in East Setauket, New York. His career output includes more than 80 technical papers, 37 US patents and 114 inventions published in the IBM Technical Disclosure Bulletin.