iTunes Sound Check Question

[Gibson88]

Hey all, I checked the Sound Check box when I went to burn a CD by mistake the other day. Next time I booted up my Mac my iTunes was going through all the songs Sound Checking them, I canceled it about 1/3 through. My question is, has iTunes done anything to a third of my music it didn't finish? If it has can someone explain what?

Thanks.

 

[GGJstudios]

iTunes: About Sound Check