Losing Powerpoint Audio during export

Does anyone have a solution that will fix the problems I'm having when exporting my PowerPoint Presentation to a MP4 or MOV file? When I record a presentation using my mic and play back the recording everything works perfect. I can see the slides and the voice narrating to each slide, however, once I export the file as a MP4 or MOV file it doens't save the Audio portion of the presentation. I contacted MS Tech Support and they say I would need a third party ad on to get it to work? Has anyone else had these problems? I would like to use the MP4 file in my webinar but need to have the slides and audio working together.

It's to confusing trying to do a screen recording with Quicktime Player..