You can change fps in prefs. There you can select something closer to NTSC or Pal or whatever. I animate to the sound also ( at 30 fps ). I place the sound with my scene in After effects or Final cut. There if needed, ( not often ) I'll speed up or slow down the animation or sound.

If you use one of the above composite programs, you can import at any fps (almost) & export at something different (NTSC, PAL . . . ).

I agree with Pure_M. The program you use to play your scene is not matching somewhere with what you exported. Good luck