Try downloading yourself ingame by typing /dl watermagic.
If that doesn't work delete your custom folder (Toribash>Custom>Watermagic) and download yourself again ingame.
I did this and it only fixed the problem partially. I myself don’t hear the hitsounds, as well as most people I play with. However, I’ll bump into a random every now and then complaining about my hitsounds that they should not be able to hear.