I agree with Jamesonsmum, I think cats respond to your tone of the voice rather than the exact name/word you are actually calling. And I would think it is probably a near impossible thing to get them to obey to a "come" command like a dog. They will come if they feel like, they don't if they don't feel like... you know how cats are.
Oliver amassed a numerous nicknames, from pancetta, sancho pancia, ciccio, panna, pupazzo, peluche, Homer (simpson), doughboy, honeypoo, booboo, poopoo head etc. etc., which are in use constantly in rotations, he responds to all. (well, of course, if he is up to it...) Heck, he comes running if we going to either kitchen or bathroom, even if we don't call him too!!