Roku express will only play background sound while watching Roku tv. Audio works fine on any other streaming service (Netflix, YouTube) any idea how to adjust Roku audio to hear voices for Roku tv.
Are you referring to "The Roku Channel"? A "Roku TV" is... well... a TV.
Sorry yes, the Roku channel
Does it happen with every "channel" or show within "The Roku Channel"? Try the various options you can find under "Volume mode" when you press the * button on your remote while you're watching something. You might also want to experiment with the Audio options found in the main Roku Settings on the Home Screen (scroll up from "Home" on the left of the screen).