The old voices were replaced by new ones in different languages and many people aren’t happy about it. This tutorial can hopefully help to fix it.
Fix for v1.32.7 (and upcoming patches?):
For Windows:
Download this and run it to fix the problem: https://1drv.ms/u/s!AjKrdUvE60XngWbIuWQcDhYewXml?e=M04nlZ
It adds the registry entry “Allow Local Files” and sets its value to 1.
You can also add it manually of course, just open “regedit.exe”, go to HKEY_CURRENT_USER\SOFTWARE\Blizzard Entertainm…
You can scroll down there to the bottom part of the post for German, English & French voice files or just follow the whole tutorial to obtain other voice files.