This is possible when your PowerPoint presentation has linked audio file (it refers to a local path on your computer). All media files more than 50 MB are linked. WAV files less than 50 MB can be embedded in 2007 and previous versions.
When you share such presentations through email or upload them on authorSTREAM, the audio file never gets shipped with the presentation. As a result, when you convert your PowerPoint presentation to video, there is no sound in the video output.
To resolve this problem, authorSTREAM has come up with a unique tool –authorSTREAM desktop. It’s a free plug-in for PowerPoint presentations. authorSTREAM desktop supports embedded audio files, audio added in PowerPoint through record narration feature of PowerPoint, and transition sound played across the slides. It supports MP3 and WAV formats, so you can use this software for linked audio files. However, authorSTREAM desktop does not support WMA audio format and special characters in the audio file name.
You can use the inbuilt upload functionality of authorSTREAM desktop, this way your audio files get shipped with your presentation. It’s a good idea to verify audio in your presentation when it gets published on authorSTREAM before proceeding for video conversion.
(Please Note: athorSTREAM desktop doesn’t support WMA audio format.)