You likely know that you can use Do Not Disturb to prevent random notifications on your iPhone from waking you at night—it’s easy to set a Do Not Disturb schedule for your usual sleeping hours. Another setting in there is important but often overlooked. If you ever use your iPhone during those Do Not Disturb hours—perhaps to read a book while a partner or roommate is asleep—you don’t want it to make any noise. To prevent that, in Settings > Do Not Disturb, make sure to set Silence to Always instead of While iPhone Is Locked.