Depends on what kind of a sound.  If it's a soundtrack, then you have to figure out where on the timeline certain beat or sound even occurs, then adjust your animation to fit.
When I'm doing various visualization presentations at work, sound effects I like to add in post production, where I mix video with various soundtracks. Either in Adobe Premiere, or Sony's Vegas Video.  They let you move and slide sound bytes to match animation, and allow you to mix multiple audio and sound tracks. Especially Vegas Video.

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