Recognition of multilingual speech in mobile applications

We evaluate different architectures to recognize multilingual speech for real-time mobile applications. In particular, we show that combining the results of several recognizers greatly outperforms other solutions such as training a single large multilingual system or using an explicit language identification system to select the appropriate recognizer. Experiments are conducted on a trilingual English-French-Mandarin mobile speech task. The data set includes Google searches, Maps queries, as well as more general inputs such as email and short message dictation. Without pre-specifying the input language, the combined system achieves comparable accuracy to that of the monolingual systems when the input language is known. The combined system is also roughly 5% absolute better than an explicit language identification approach, and 10% better than a single large multilingual system.