Video without sound

Why does my video done on the 20th june has any sound?
I’ve prepared this a whole day cause its a final term work…and now my teacher tells me there is no sound on my video? And she is right, i just came back to verify and its like i have no sound but i was talking the whole video…how can i put the sound on?

Hi @Stephanie_Fournier, could you please send me the link to the presentation or video? What did you use to create your final term work? Did you use Prezi Video?