KAK, I agree. my kitties know the word 'treats' and also 'tuna'.............. I say it like "tuuuunnnaaaa" and they all 3 come running. sometimes I even just get the can opener out and rattle it and they are there within a few seconds.
I think they hear what they WANT to hear. for instance, mine act like they don't know what the word 'no' means