Combination of Multiple Speech Transcription Methods for Vocabulary Independent Search

Off late, most systems use large vocabulary continuous speech recognition tools to produce word transcripts which have indexed transcripts and query terms retrieved from the index. However, query terms that are not part of the recognizer's vocabulary cannot be retrieved, thereby affecting the recall of the search. Such terms can be retrieved using phonetic search methods. Phonetic transcripts can be generated by expanding the word transcripts into phones using the baseforms in the dictionary. In addition, advanced systems can provide phonetic transcripts using sub-word based language models. However, these phonetic transcripts suffer from inaccuracy and do not provide a good alternative to word transcripts.