As the Master Chief steps out of his cryopod on the level The Pillar of Autumn, Shephard presses a few buttons on an adjacent control panel in Remastered graphics. There are a few accompanying beeping sounds for the button pressing animations, but in Legacy graphics, Shephard doesn’t touch the control panel.
Unfortunately, the beeping sounds still play with Legacy graphics selected. Perhaps this could be fixed in a future audio update to CEA?