A top priority goes to maintaining the person's sense of night and day with changes in light and dark as well as noisy versus quiet hours of time. Finally, most residential facilities turn the loud speakers and TVs off and the lights down at night.
The importance of regular schedules for sensory stimulation between meals and after the evening meal in maintaining circadian rhythms has not been established. Experience suggests that the schedule of the 24-hour cycle requires a regular sequence of all of the activities that happen to the person.