Mmmm, it's that sound file that is corrupt. Try reinstalling with the Digital download. How to do it:
1) Create and verify a new Blizzard Account, if you don't have one already:
2) After logging in, click on "Games" under My Account Controls. Or, click here:
3) Click the Add a New Game button. Or click this:
4) Enter your CD-Key and select your language, when prompted.
5) You can now download the game by clicking the Windows or Apple logos, depending on your OS.
6) Install using the Game Key shown by clicking "[View Game Key]".
The Chat Gem Lives!