I'm working on french voice recognition, i have some results but not enough accurate at the moment.
The key to make Sphinx work is in the makefile.in and makefile.am that have to be modified to integrate the targeted foreign language, changing language on the fly is not possible, at least with the code i have.
The documentation is very rich but also spreading in every way and sometimes showing big holes so not easy to have a global overview about Sphinx :)
Archives of french language can be found at the Le Mans university under the LIUM name.
Seems that the train part is the other key to have accurate recognition but with a bad microphone not that easy.
I'm also looking inside of perlbox which is a good point to start from.