On the latest A321 jets in the TCX fleet: pitch rate (degrees per second) is constantly monitored and when predicted pitch (current pitch + predicted pitch in one second) exceeds 8.25° this triggers the synthetic "Pitch Pitch" call.
Thus you can sit steadily at 8°all day without a peep out of the thing (although your colleague may have something to say on the matter) and you can also never get past 4° but still trigger the call if you flare vigourously enough (I have on a couple of occasions).