Before a call can be made to any of the standard DAPI functions, and after you have the handle to a language, you must select the language. This is accomplished through the TextToSpeechSelectLang call. You must select the language before each call to any DAPI function that does not take in a valid LPTTS_HANDLE_T handle. The first parameter to TextToSpeechSelectLang must be NULL. The second parameter is the handle retrieved from TextToSpeechStartLang. The return value from TextToSpeechSelectLang is a Boolean value: TRUE signifies success and FALSE signifies failure.
Example:
TextToSpeechSelectLang(NULL,UKhandle)