Spoken document retrieval (SDR) systems must be vocabulary-free in order to deal with arbitrary query words because a user often searches the section where a query word is spoken, and query words are liable to be special terms that are not included in a speech recognizer's dictionary. We have previously proposed new subword models, such as the 1/2 phone model, the 1/3 phone model, and the sub-phonetic segment (SPS) model, and have confirmed the effectiveness of these models for SDR . These models are more sophisticated on the time axis than phoneme models such as the triphone model. The present paper proposes an integration method of plural retrieval results that are obtained from each subword model and demonstrates the performance improvement through experiments using an actual presentation speech corpus.
Bibliographic reference. Itoh, Yoshiaki / Iwata, Kohei / Kojima, Kazunori / Ishigame, Masaaki / Tanaka, Kazuyo / Lee, Shi-wook (2007): "An integration method of retrieval results using plural subword models for vocabulary-free spoken document retrieval", In INTERSPEECH-2007, 2389-2392.