Language model adaptation using WWW documents obtained by utterance-based queries

In this paper, we consider the estimation of topic specific Language Models (LM) by exploiting documents from the World Wide Web (WWW). We focus on the quality of the generated queries and propose a novel query generation method. In contrast to the n-gram based queries used in past works, our approach relies on utterances as queries candidates. The proposed approach does not rely on any language specific information other than the initial in-domain training text. We have conducted experiments with Web texts of size 0-150 million words, and we have shown that despite not using any language specific information, the proposed approach results in up to 1.1% absolute Word Error Rate (WER) improvement as compared to keyword-based approaches. The proposed approach reduces the WER by 6.3% absolute in our experiments, compared to an in-domain LM without considering any Web data.