The Clarissa conversational procedure assistant is now installed on
the International Space Station (ISS), ready to be used the first week
of March 2005.  The system uses a Nuance Communications speech
recognition engine with special language models compiled from typed
unification grammars.  The grammar is constructed from a large general
purpose grammar, which is specialized using Experience Based Learning
(EBL) based on transcriptions of astronaut speech.  In principle the
grammar could be continually improved by using more speech as the
system is used.  This grammar is compiled into a PCFG for the Nuance
recognizer using the Nuance grammar compiler.  The system features an
open microphone speech recognition system, which continually listens
to the users, and only accepts utterances which have meaning for it,
given the context of the dialogue. 

Na dann viel Glück... "Dave, ich kann Dich nicht verstehen! Bitte wiederhole Dein Kommando. Sag "Hilfe" für Hilfe."