You sure? you should upload the .capx for us to check.
Anyway, even if a sound is not on Loop, it can be played multiple times at once if the event is asking it to, and the event will ask it to play it on every tick as long as it meets all the conditions. eg. you set Life to -1, and the event checks if Life > 0. Well, this event is effectively true and will keep playing the actions and sounds every tick.