These are the Dictation packs from Windows Phone 8 SDK. You can find and download them here http://www.mediafire.com/wp8dictation. Check your language code here http://www.microsoft.com/resources/m...indows%20Vista , the last four numbers of the LCID is the code you are looking for.
They have the larger size than the wp7 version. In addition, there are some other langs which are not available yet.
+ Download and Unrar.
+ If your lang is already available, use a file browser such as Windows Phone Device Manager 1.10 to replace the dictation file with the new one. The dictation files are stored in /windows folder.
+ If your lang is not available yet (like mine ), rename the the dictation file. Example: I used Native Keyboard to patch Vietnamese keyboad layout into the original Spanish keyboard. So that, i rename the dictation file from dictionary.042A.dat to dictionary.0C0A.dat and replace it then.
+ Reboot your phone.