As far as I can tell, Class Abilities (like Wound or Jinx) trigger silently. It would be great if each ability had a unique sound. With Wound, for example, it flashes the Wound symbol on my hero, but I’m not always looking at the bottom of the screen.
Given that some of these abilities can trigger multiple times per second, it would be wise to have some limit on the frequency with which an ability’s sound effect is played, e.g. once per two seconds.