Sona passive audio plays several times
My last game, when playing Sona, I had my autoattack empowered from her passive and Q (so her next auto would deal extra magic damage and nothing else). Upon finding a vision ward in a bush, I autoattacked it five times, and each time it played the audio as though I was using my empowered basic attack although my passive was not reset.
I believe that attacking a ward isn't supposed to use up her empowered auto, but I don't think the special sound effect is supposed to play either.