Abstract: A non-invasive brain assessment monitor is disclosed. An embodiment of the monitor includes a head-mounted brain sensor which passively senses acoustic signals generated from pulsing blood flow through a patient's brain. A reference sensor may be mounted at another location on the patient's body to sense an arterial pulse, and the signals from the brain sensor and reference sensor may be compared. Another embodiment includes transmitters which generate acoustic signals in the brain which are also detected by the brain sensor. The brain assessment monitor may be used to detect conditions such as head trauma, stroke and hemorrhage.