Laura Foley has posted an ingenious method here that will loop sequences of animations on a PowerPoint slide. Laura provides excellent instructions in her post, and I successfully followed them this evening. These are the basic steps to follow:
1. Starting with a slide that has several animated objects, create an audio file in PowerPoint using the option on the Insert tab to the right in the Media section. Go to Audio . . . .Record audio.
2. Record an audio file that is the length you want one sequence of the animations to run.
3. Select the audio file on the slide, and on the Audio Tools . . . Playback tab check the options for 'Loop until Stopped'; 'Hide During Show', and 'Mute' in the Volume drop down menu.
4. Click play on the audio file. Pause it at intervals where you want the animated objects to appear, and then select Add Bookmark on the Playback tab.
5. Right click on each of the animated objects and add a trigger under Timing that is set to start on the click of the recorded sound and on the play of a specific bookmark.
6. Add 'exit' animation sequences that are set to start at a bookmark at the end of the audio file.
You'll have to excuse the unartful design, but the below gif shows how this method creates a continuously looping animation sequence.