Hi Antonio @tonys87 ,
What happens in the video, is just Pixels being colored. Fitting the Audio is usually a manual process, sort of like Lip Syncing, but then the other way around.
There are some Addons that can sync some audio to what happens in a 3D Scene, but when the video is already Rendered, you can’t sync sounds automatically anymore….
This will probably be possible with AI in the future (or maybe it already is).