Why is the sound of my videos off by default on the WebApp?

Per default, the browsers block audio when auto-playing is set for a web player. They did that to prevent your computer from suddenly playing loud content when a page is loaded. 

We can turn off auto-play for the players in your WebApp. The only disadvantage is that viewers would have to click on "PLAY" in the web player to play content. But that is probably not an issue as they will see a big Play Button in the player.