If the language defined for the application profile does not specify the required language, you can change the value of the System : Current language system variable (SV39), using the ReceiveData, AssignData, GetKey, or GetData state table actions in your voice application.
For example, your voice application can prompt callers to press a key to request a specific language (“Por español, prensa el uno... ...for English, press two... ...pour Français, appuyez sur trois... ...Für Deutsch, bitte drücken Sie auf die Vier.”) Then set the System : Current language system variable (SV39) to the code for the language chosen (the codes are listed in the Languages window (Configuration —> Languages). The value of SV39 specifies which language database is to be used for prompts.