Ты можешь сменить озвучку сам, по данной тобой ссылке есть небольшой FAQ:
How to add my own voice file and alert?
Add your own file eg. myspell.mp3 (must be .mp3 or .ogg here) in the file folder /Interface/GSASound.(by default, but you can also use any other one under your wow root)
Type /gsa to show the config, then select "Custom" ,add and config your sound alerts here.
How to make my own voice set?
If you want a voice set other than English or Chinese, try to make your voice files with the same names as the files in the folder "Voice_enUS", then copy and overwrite the original files. Select "Enlish (female)" in game, then your own voice set works.
If you voice set is very good, and you want to share it with others, just email me and add your voice files as attachment.