^ I dunno, Randi...Decades of Trek with dubbing? I think the cost of realism (in terms of shear tedium and annoyance for the audience, e.g., me!) would be far too high.
So I just accept the universal translator as it is. Hey, it's no worse than the Babble fish, after all.
Especially since the universal translator is, in itself, one of the most unrealistic things in Star Trek, and I am not exaggerating. Have you ever seen what a computer translation looks like? Try AltaVista or some other online translator - they are great only if you want to have a good laugh.

OK, I am not saying that there can't be more sophisticated programs, with a better vocabulary, more idioms and so on, sometime in the future... but any linguist will tell you that there is no way in hell that a computer device could ever perform successful translations from one language to another, all by itself. You'd get something like the infamous "out of sight, out of mind" = "invisible, insane" computer translation from English to Chinese and back into English. In speech, so much depends on context, so the only successful machine translator would have to be AI. And in that case, why bother at all? Why not have human translators who use computerized dictionaries to be able to translate quicker?
And let's not even mention how unrealistic it is to have that device translate the words accurately at the same time as they are coming out of a person's mouth (without even having time to consider the meaning of the entire sentence). In reality, a non-AI machine working as a simultaneous interpreter would create such a high probability of error that the communication might completely break down.