Paper: Position Specific Posterior Lattices For Indexing Speech

ACL ID P05-1055
Title Position Specific Posterior Lattices For Indexing Speech
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 2005
Authors

The paper presents the Position Specific Posterior Lattice, a novel representation of automatic speech recognition lattices that naturally lends itself to efficient in- dexing of position information and subse- quent relevance ranking of spoken docu- ments using proximity. In experiments performed on a collec- tion of lecture recordings — MIT iCam- pus data — the spoken document rank- ing accuracy was improved by 20% rela- tive over the commonly used baseline of indexing the 1-best output from an auto- matic speech recognizer. The Mean Aver- age Precision (MAP) increased from 0.53 when using 1-best output to 0.62 when us- ing the new lattice representation. The ref- erence used for evaluation is the output of a standard retrieval engine working on the manual transcription of the speech...