Word recognition in continuous speech using a phonological based two-network matching parser and a synthesis based prediction

The present state of the SPICOS project, a speech understanding dialog system for fluent German speech using a 1000-word lexicon, is described. The first system version was demonstrated in 1986; the second will be finished in 1990. The authors present new SPICOS I results and some preliminary SPICOS II results with regard to phoneme and word recognition. A data-driven two-network matching parser compares the input network of alternative phonological units with a word lexicon organized as a cyclic network. This lexicon not only contains the standard pronunciation but also models interword and intraword assimilations. Substitutions, deletions, and insertions of single phonemes are taken into account during the match. The output of the parser is a network of word hypotheses. An additional module predicts long words after parts of them have already been hypothesized. Then the long word patterns are synthesized concatenating demisyllables and are verified parametrically. Well-matched words are added to the output network