If ejection operation sounds are too loud during paper ejection, select the menus on the printer's control panel as described below. However, this may lower print speed. Also, when printing density is high, shift sort is being performed, or stapling is being performed, the printer automatically aligns the paper and may not be able to reduce the noise level during paper ejection.
Settings > General Settings > Printer Settings > Finisher Tray Setting > Quiet Mode