19. A system for translating voiced phrases from a first language into a second language, comprising: a store holding a collection of phrases in the second language; input means for accepting a voiced input phrase in the first language; characterization means connected to said input means for determining which of said collection of phrases corresponds to said voiced input phrase, said characterization means comprising speech recognition means configured to operate as keyword detection means, for detecting in said input phrase the presence of members of a predetermined set of keywords or keyword parts in said first language, said predetermined set being smaller than the total number, Z, of words in the phrases in said first language which would correspond to said collection of phrases, said speech recognition means having a recognition vocabulary of P words, where P is smaller than said total number Z; lookup means arranged to access said store to address that phrase which corresponds to the input phrase in dependence upon the keyword or keyword parts or combinations thereof detected by the characterization means in the input phrase; and output means responsive to said lookup means for outputting said phrase in said second language.
19. A system for translating voiced phrases from a first language into a second language, comprising: a store holding a collection of phrases in the second language; input means for accepting a voiced input phrase in the first language; characterization means connected to said input means for determining which of said collection of phrases corresponds to said voiced input phrase, said characterization means comprising speech recognition means configured to operate as keyword detection means, for detecting in said input phrase the presence of members of a predetermined set of keywords or keyword parts in said first language, said predetermined set being smaller than the total number, Z, of words in the phrases in said first language which would correspond to said collection of phrases, said speech recognition means having a recognition vocabulary of P words, where P is smaller than said total number Z; lookup means arranged to access said store to address that phrase which corresponds to the input phrase in dependence upon the keyword or keyword parts or combinations thereof detected by the characterization means in the input phrase; and output means responsive to said lookup means for outputting said phrase in said second language. 21. A system according to claim 19 in which the characterization means is operable in the case that more than one keyword is recognized in the input phrase to make use of their relative positions within the input phrase for the purpose of distinguishing between phrases of the collection.