Can one deactivate the global chat ?

[Putin]

Hi there fellows.
I downloaded the zombiepack but there is always a global chat, as soon as the zombiess get the order to attack. The author said that he'll fix that but it seems he did not. Now I wanted to ask, if I could just deactivate the global chat with a script or trigger. Hope you can help me.
Thanks already and have a nice remaining weekend.