17. The system of claim 14 , wherein the computer-executable instructions further configure the one or more processors to: smooth the separate language models with a shared background model using a common vocabulary.
17. The system of claim 14 , wherein the computer-executable instructions further configure the one or more processors to: smooth the separate language models with a shared background model using a common vocabulary. 18. The system of claim 17 , wherein the shared background model employs an open-vocabulary language model having at least some out-of-vocabulary terms with respect to at least one of the separate language models.