I used Gnome Shell for quite some time instead of Unity and in X-Chat I could hear a "thud" sound whenever my nick is highlighted. However now since I switched back to Unity that sound doesn't play at all.
I'm puzzled about this because sound works on every app I launch. So I went to the Sound app to figure things out and in the "sound effects" tab I noticed the alert volume was all the way to zero, so I reversed it all the way to 100 percent but it didn't solve anything.
Now I'm fresh out of ideas about this problem and I need help.