If I want to have agents with ‘ears’, meaning that I want the agents in a scene to respond to some audios, how do I do that?
AudioListener component just defines a point of processing the audio and reflect it out of the computers speakers. The position of it only matters if you are using 3D sound.
As for the agents that respond to audio sources, what we have done in one of our projects is, we gave a hearing radius to the agent (Basically a trigger sphere) and another noise radius to everything we want it to respond to. Then we just go in a switch loop in the OnTriggerEnter method for the hearing radius and process the actions based on the noise source.