There could be many reasons why you can't hear sound or music.
- Please try to restart your device.
- Remove apps like Youtube, Safari, Spotify, etc from background (No need to uninstall them).
- Please try to increase volume when earphones are plugged in.
Some users wrote us about a dirty headphone jack. The device accidentally assumed there where earphones plugged in.
Important: please be very careful when cleaning your headphone, Lightning or USB jack.