Pause and restart audio when in Play mode

I've imported an mp3 track onto a Keynote slide, and I want to be able to pause and restart the audio when in Play mode. (It's for a language class and students need time to be able to make notes.)

When it's not in Play mode there's no problem. The sound icon shows on the screen and I can click pause and play. When I try to pause when in Play it automatically moves me onto the next slide.

Any ideas please?

Thanks in advance.