Click the B button in the panel to enter the Predefined Music Playing Mode.
Click the D button in the panel to enter the Replay Mode.
Users may want to play the predefined music stored on the device. If so, users may first press B to enter Predefined Music Mode. After the display changes, the user can hear the predefined music playing several times. To exit the Predefined Music Mode, the user could press # when the music stops.
Users can press D to get into the Replay Mode to listen to what they recorded before. I could hear the song immediately after users clicked the button, and after several times replaying, users could press # to `jump out of the Replay Mode or wait for some time and listen to my song one more time.
