Posteriorgram based approaches in keyword search

In this work, two different keyword search (KWS) methods are proposed in order to improve the existing KWS system which is based on large vocabulary continuous speech recognition (LVCSR) and weighted finite state transducers (WFST). In the first method, a symbolic index is generated by applying vector quantization to the posteriorgram representation of the audio and then WFST based search is performed. In the second method, KWS was done with the subsequence dynamic time warping (sDTW) algorithm which is commonly used in the query-by-example spoken term detection (QbE-STD) tasks. As a result of the experiments, it has been observed that when combined with the existing KWS system, the proposed systems improve the performance especially for the out-of-vocabulary (OOV) queries.