4. The method of claim 3 , further comprising: classifying the background environment periodically throughout a call and selecting new acoustic models that match new background environment classifications for the call.
4. The method of claim 3 , further comprising: classifying the background environment periodically throughout a call and selecting new acoustic models that match new background environment classifications for the call. 5. The method of claim 4 , wherein when a first acoustic model is selected in a call based on the new background environment classifications a second acoustic model is selected to substitute the first, and the method further comprises: starting the second acoustic model with an initial state associated with a previous state where the first acoustic model ended.