An improved and non-destructive test method and system utilizes ultrasound wave energy to automatically judge the sealing effectiveness of a sealed compartment such as the cabin of a motor vehicle or aircraft. An ultrasonic transmitter generates ultrasound energy of a specified frequency within the compartment, and one or more ultrasound sensors outside the volume detect the presence and amplitude of ultrasound energy at the specified frequency. Alternatively, the transmitter can be configured to generate ultrasound energy outside the compartment, and the sensors can be arranged to detect ultrasound energy within the compartment. The detected energy level is compared to a calibrated threshold, and a leak indication is generated if the threshold is exceeded. In a factory setting, the volume can be passed through an arched array of ultrasound sensors strategically located to detect the presence and amplitude of ultrasound energy of the specified frequency in the vicinity of potential leakage areas of the compartment. If the position of the compartment relative to the sensor array is known, the leak indication can be used to pinpoint the location of the leak, and to suggest specific corrective action.