My computer sounds like alvin and the chipmunks ive tried all i know..its not working...?

when ever i listen to a movie or radio station the people sound like the chipmunks. i didnt apply any special effect. i dont know what to do. i have looked in every part of my computer to fix this but nothing is working. one moment i had sound..next my toddler bumps into my computer..then no sound..when i got it back working i noticed that everything sounds sped up and like they all inhaled helium..what do i do beside buy new speakers that i dont have the money for..and what if i get new speakers and the sound still does the same thing... windows xp ...