Speech Recognition on Code-Switching Among the Chinese Dialects

We propose an integrated approach to do automatic speech recognition on code-switching utterances, where speakers switch back and forth between at least 2 languages. This one-pass framework avoids the degradation of accuracy due to the imperfectly intermediate decisions of language detection and language identification. It is based on a three-layer recognition scheme, which consists of a mixed-language HMM-based acoustic model, a knowledge-based plus data-driven probabilistic pronunciation model, and a tree-structured searching net. The traditional multi-pass recognizer including language boundary detection, language identification and language-dependent speech recognition is also implemented for comparison. Experimental results show that the proposed approach, with a much simpler recognition scheme, could achieve as high accuracy as that could be achieved by using the traditional approach