Using AI Perception (hearing) on non-pawns?

I have been playing with the AI Perception system today, adding an AI Perception component to a stationary actor (lamp posts) and a AI Perception Stimuli Source component to a moving actor (car), using only “hearing”. So far, I have had 0 success with this setup. I set the lamp to trigger a particle system explosion if the lamp detects anything, so it’s obvious.

I copy/pasted the same AI Perception Stimuli component to my character and the lamps sometimes triggered the explosion.

I definitely have a lack of understanding here. What does it mean to “hear” another actor? Is it listening for actual played audio? In my scenario, the cars have audio attached and the player doesn’t so that makes me think it isn’t actually “listening” to audio … so it’s somehow simulated. But I don’t get it.

Overall, I am trying to create a setup where audio played from one source can be detected by another source. So if I have a setup where I press enter to trigger a beep, I want other actors to be able to detect that… if this is even possible. I thought the above might be they key but so far it’s just been failure after frustrating failure.

same here, it seems only ai can do stiumuli