The .wav file requires the mu-law format, 8,000kHz/8-bit mono. When you want to create an Application Prompt from a .wav file, the .wav file must use the same encoding, G.711 PCM mu-law, that all Caller Application prompts use. You must create an empty application prompt in the usual way.
If the encoding is correct, then you must simply drag the .wav file into the Voice Control of the Caller Applications Editor Prompt property page and save the file.
If the encoding is not correct, then you must use an application such as Microsoft Sound Recorder to create a file with the correct encoding. Use the following steps to perform this.
You can then drag and drop the resulting file into the Caller Applications Editor Voice Control.