Dear Samsung Member,
Greetings from Samsung Customer Support!
Kindly perform the below mentioned steps and be assured it would resolve your issue:
1) Disconnect anything plugged into the headphone jack like, selfie stick, headphone, Bluetooth, etc.
2) Check device volume settings:
Apps screen > Settings > Sound and vibration > Volume > Drag the volume adjustment bar left or right to increase or decrease the device volume
If the issue still persists kindly attach the log file and send it to us in the Samsung member application(attach when the issue occurs within first 15 minutes):-
Samsung Members App > Feedback > Error Report > Attach log file.
Thank you for writing to Samsung.
Samsung Customer Support