This study seeks to examine the effects of overnight noise reduction in critically ill patients who are receiving mechanical ventilation. The investigators will randomly place subjects into one of three groups: 1) usual care 2) overnight earplugs 3) overnight earplugs and noise-canceling headphones. The investigators will monitor for safety, and will measure the amount of delirium experienced by subjects, record the amount of sedating and painkilling medicines required, and measure sleep quality during the study, among other information. The investigators will also measure noise levels experienced by patients in each group. The investigators predict that the use of overnight noise reduction will be safe and will reduce the amount of delirium by improving the quality of sleep in critically ill patients.