Program to check if MP3's have skips?

It seems like it should exist.. I just don't know where to find it or what this process is called.

When tracks are being ripped and encoded, what does the encoder do if data is missing because the cd is scratched?
What string would I look for when reading the mp3 code?

I suppose it would do the same thing a CD player does: it makes srtange hops. At least my encoder does that. Therefor there can't be a program that does that (except an extremly advanced sound analyzer).