The diagnosis of head trauma or other medical conditions indicating a need for ICP monitoring, the decision to place an intraventricular catheter and the duration of ICP monitoring are at the discretion of the patient's clinical care team and independent of this study. With the exception of simultaneous use of the non-invasive acoustical HS-1000 monitoring system and ambient noise level measurements within the patient's room, all other patient care, including clinical evaluations and treatments, is independent of this study. No HS-1000 data will be displayed and will not be used in clinical decision making.