I figured out the main contributing factor: When I have the vibrate/sound switch in silent, there is no audio through the speakers when I play the video within the Sync app. I do however have audio through a headset when plugged in. When I have that switch in the ON position (normal ring volume/sound) there is audio through the headset and speakers. This appears to be a Sync app issue. Maybe a minor bug. My iPhone 6 does not do this in any other application, to include iCloud videos, Youtube, and third party apps that I play videos through (Path, among others for example). So, in my unprofessional opinion, possible bug? Thanks, Matt