How do I enable Silent Entry Mode so the safe doesn't make any sounds?

Tap the touchpad to wake up the lock face, then press and hold the [*] key for 3 seconds. The yellow LED will flash 2 times, indicating the safe is now in silent entry mode. To turn the sound back on, press and hold [*] for 3 seconds again — the yellow LED will flash 2 times and a beep will confirm that sound has been restored. (Page 10)