How to disable system notification sounds in KDE apps?

[Colin Brace]

Hello,

Can someone tell me how to disable the highly irritating noises KDE apps 
make?

I logged into a KDE session, went to the KDE Control Center --> Sound 
and multimedia, and found an option to turnoff system notification 
sounds, checked "Apply to all" and activated it, but programs like 
Kontact still make that obnoxious breaking-glass sound on errors under 
Gnome. How can KDE users stand it?

TIA