Sound designers create the soundscape for an animation. In animation, there are no natural sounds to work with (as there would be when filming live action) so everything sound in animation is created from scratch by sound designers. For this activity take a sound clip from wavesource, or freesound, or another website and create a short animation to accompany that sound.
Find a sound you would like to use.
Something between 2-3 seconds preferably
Maybe characters talking, a battle going one, etc.
Come up with an idea to animate that sound
It doesn't have to be a direct copy of what the sound it from, you can get creative and come up with your own ideas
Create you animation
Export animation as an mp4 file