A multilingual Automatic Speech Recognition (ASR) engine embedded on Personal Digital Assistant (PDA)

In the paper, we describe a multilingual ASR engine embedded on PDA. Our ASR can support multiple languages including Mandarin, Taiwanese and English simultaneously based on a unified three-layer framework, and a one-stage searching strategy. In the framework, there is a unified acoustic models for all the considered languages, a multiple pronunciation lexicon and a searching network, whose nodes represent the Chinese characters and English syllables with their multiple pronunciations. Under the architecture the system can not only reduce its memory and computational complexity but also deal with the issues about a character with multiple pronunciations. In general, the computer resource of PDA is quite limited when compared to PC. In this paper, much work has been done to alleviate the limitation of PDA. The experimental results show the system has good performance where the recognition rate achieves about 90% in the voiced command task with limited vocabulary.