Can I use music with synchronized license for games?

Website like AutoHero provides music without royalties with synchronization rights.

End user license states

Your purchase of the Sounds includes only synchronization rights

You may not change or alter in any way any Music and sound effects of AudioHero.com that are owned or represented by AudioHero.com (for example, by adding instruments or lyrics).

I want to use certain sections of a sound effect.
Would this be a problem since I am not "synchronizing" the whole piece?

Since this is a game, the pieces of music are played one on top of the other. Does this count as "altering" the piece of music?

I am a computer science student with no legal or music background, so I am lost with most technical words.