Improvements in phone based audio search via constrained match with high order confusion estimates

This paper investigates an approximate similarity measure for searching in phone based audio transcripts. The baseline method combines elements found in the literature to form an approach based on a phonetic confusion matrix that is used to determine the similarity of an audio document and a query, both of which are parsed into phone N-grams. Experimental results show comparable performance to other approaches in the literature. Extensions of the approach are developed based on a constrained form of the similarity measure that can take into consideration the system dependent errors that can occur. This is done by accounting for higher order confusions, namely of phone bi-grams and tri-grams. Results show improved performance across a variety of system configurations.