Do you get a message saying this feature is not available in American English? Check the following.
Do you have the en_US.srd file in the ASR folder, and using either English_American_Jack.vpm or English_American_Jill.vpm TTS voice file? Also have you got either a complete map of US lower 49 or a complete NA? [i.e. no tiles missing, not even one].

If all seems correct as above, redownload and replace all the ASR/SRX ensuring they are the ASR'2' files for 2012> devices, not the ASR'1' 2011 files.