Audio Controller / Sending event when audio plays from sequencer

Hi, I stumbled upon a problem: does anybody know how to observe what audio goes thorugh your sequencer’s audio track? We use lip sync plugin, which requires to call a function when audio is played. I figured out that we can use dispatchers and call that function automatically when audio is played in audio track. Problem is, that we can’t make it work with audio tracks, since there is no way of binding events to them, and they don’t seem to have any context. Is there a way to somehow bind an event to whenever an audio is played? Or maybe something inside sound class? There is variable named ‘Output Target’ there, but choosing Controller doesn’t seem to change anything.

Could you use an Event Track and make an event key at the start of each audio clip and have that event call the other system? Event Tracks are improved in 4.23/4.24 and easier to use.