4. A hardware computer storage medium encoded with a computer program, causing the computer to execute steps comprising: decoding a representation of a speech signal using a position-dependent phonetic language model that provides probabilities of sequences of position-dependent phonetic tokens wherein each position-dependent phonetic token comprises a phone and a position identifier that identifies a position within a syllable, wherein decoding produces at least one sequence of position-dependent phonetic tokens; receiving a symbol represented by a portion of the speech signal, wherein the symbol is not part of the language of a lexicon; and annotating a lexicon by storing a sequence of position-dependent phonetic tokens as a pronunciation for the symbol that is not part of the language of the lexicon, wherein annotating the lexicon further comprises identifying syllable boundaries from the position-dependent phonetic tokens and placing syllable boundaries in the lexicon.
4. A hardware computer storage medium encoded with a computer program, causing the computer to execute steps comprising: decoding a representation of a speech signal using a position-dependent phonetic language model that provides probabilities of sequences of position-dependent phonetic tokens wherein each position-dependent phonetic token comprises a phone and a position identifier that identifies a position within a syllable, wherein decoding produces at least one sequence of position-dependent phonetic tokens; receiving a symbol represented by a portion of the speech signal, wherein the symbol is not part of the language of a lexicon; and annotating a lexicon by storing a sequence of position-dependent phonetic tokens as a pronunciation for the symbol that is not part of the language of the lexicon, wherein annotating the lexicon further comprises identifying syllable boundaries from the position-dependent phonetic tokens and placing syllable boundaries in the lexicon. 5. The hardware computer storage medium of claim 4 wherein a position identifier is one of a group of position identifiers consisting of onset consonant and coda consonant.