I'll bite :) There's a couple of research texts that I'd suggest make
"listening" an attentive activity higher up the cognitive than
hearing. Auditory neuroscience: Schnupp, Nelken and King (2011) and
Thinking in Sound: Bigand and McAdams both talk about "hearing" mainly
at the physioacoustic (signal perceptual) level, whereas "listening
experiments" tend to focus on the structural and semantic processing
faculties.
Of course that's an over-rigid appeal to scientific words, and I
appreciate your saying it can kinda work with the words exchanged.
Bit like the tussle we once had here over "ethics" versus "morals" :)
There's a bit of critical thinking that I'd suggest makes the distinction moot here:
Unity could have said 'listen', and given the insane mismatch between their past actions and the current rather predictable response, there'd be precious little comfort the sentence "We Have <Either> You" could provide compared to whatever their next actions are.
With all your research I'm sure you've come across this concept in the often quoted form: "actions speak louder than words"
(And for posterity, they even said they're listening: they just don't open with it...)