You may change the background image and music/sound by swiping to the right and left on your meditation screen while listening to your meditation.
The volume control for your sound/music is found on the bottom of your meditation screen.
(Android = Speaker 📢 iOS = Music Symbol🎵)
Your device volume controls the reader's voice.
If you are having a problem with your volume, please clear your device cache' and turn your device off/on for a reboot.