Specific contributions of the ARPA SUR project to speech sciences
Wayne A. Lea, June E. Shoup · The Journal of the Acoustical Society of America · 1977
This critical review of the recent ARPA Speech Understanding Research (SUR) project emphasizes the basic speech science results (only some of which were incorporated into the final systems). ARPA SUR provided significant progress in such parameter extraction methods as pitch detection and formant tracking. Advanced methods of speech segmentation and labeling ranged from allophonelike acoustic templates to lattices of alternative phonetic units, to quasiphonemic labeling, with emphasis on manner classes rather than place of articulation. The phonological tie between small- and large-unit recognition involved tradeoffs between extensive sets of alternative lexical baseforms and large sets of phonological rules. The syllable was promoted as a more basic unit than the phoneme, but difficulties arose with the use of syllable boundaries in baseforms and rules. Prosodic features were demonstrated as useful for determining sentence structure and confirming lexical hypotheses, but were not fully tested within any system. ATN grammars, semantic networks, and breadth-first parsers were effective for speech analysis, provided they were used to constrain system choices rather than simply be good models of language. [Work supported by Tri-Services and ARPA.]