Samsung
Mute Calls and Alarms by Turning Your Phone Over auf Samsung
Samsung phones can silence an incoming call or a ringing alarm through a motion gesture instead of a button press. Turning the device face down, or holding your hand flat over the screen, tells the system to mute the sound immediately. This works independently of the ring volume setting, which is why muting can fail even when the volume itself looks correct.
The function that handles this is called Mute with gestures, part of the motion controls in Samsung One UI. If calls or alarms keep ringing after you flip the phone, this option is usually disabled rather than broken.
Where to turn it on
Go to Tap on Settings ➔ Tap on Advanced features ➔ Tap on Motions and gestures ➔ Enable or disable Mute with gestures. Enabling the toggle reactivates both the flip-to-mute and hand-cover behavior at once; there is no separate switch for each gesture.
Keep in mind this setting only mutes sound, it does not decline the call or stop the alarm from continuing to run in the background. If you want calls rejected outright, a Do Not Disturb schedule or call blocking is the better fix. Also, if the phone is inside a case or on a soft surface, the motion sensor may not register the flip reliably, so the gesture can feel inconsistent even with the setting turned on.