Twenty-Five Years of Evolution in Speech and Language Processing

In this article, we summarize the evolution of speech and language processing (SLP) in the past 25 years. We first provide a snapshot of popular research topics and the associated state of the art (SOTA) in various subfields of SLP 25 years ago, and then highlight the shift in research topics over the years. We describe the major breakthroughs in each of the subfields and the main driving forces that led us to the SOTA today. Societal impacts and potential future directions are also discussed.

The year 2023 marks the 75th anniversary of the IEEE Signal Processing Society (SPS). Technologies have been significantly advanced in these 75 years, and society has been greatly impacted by these advances. For example, the mobile Internet has greatly changed people’s lifestyles. Researchers and practitioners in signal processing have contributed their share to these progresses.

In this article, we concentrate on the field of SLP, which is the scope covered by the IEEE Speech and Language Processing Technical Committee (SLTC), and summarize the major technological developments in the field and the key societal impacts caused by these advances in the past 25 years.

As part of the SPS, the SLTC serves, promotes, and influences all the technical areas of SLP, including automatic speech recognition (ASR), speech synthesis [often referred to as text to speech (TTS)], speaker recognition (SPR) and diarization, language identification (LID), speech enhancement, speech coding, speech perception, language understanding, and dialog systems.

The SLTC can trace its roots back to the Institute of Radio Engineers Audio Group, founded in 1947. In 1969, this audio group established the Speech Processing and Sensory Aids Technical Committee. “Sensory Aids” was dropped from the name in the early 1970s. For more than 30 years, it remained the Speech Processing Technical Committee. In 2006, its scope was expanded, and its name was officially changed to the SLTC.