How do I enable or disable Quiet Mode on the HP Envy 6400e?

Quiet Mode can be turned on or off through the HP Smart app by tapping the printer image on the Home screen and tapping Quiet Mode to change the setting. Alternatively, open the Embedded Web Server (EWS), click the Settings tab, select Quiet Mode in the Preferences section, and click Apply. Note that Quiet Mode only reduces noise when printing with Better print quality on plain paper — it has no effect when printing photos, envelopes, or using Draft or Best quality.