After listening to the "stall stall" part of CONF iture's sound track several times over, I've come to the conclusion that Airbus has done an excellent job of providing a warning sound that just naturally becomes part of the background commotion with repetition.
Maybe they really should tell you something that you really might need to know like "Alternate Law" or as in the case of the Perpignan A320, "Direct Law." One time, clearly enunciated, should be enough.