Abstract: A pressure sensing device for coupling to a cannula and receiving respiratory breathing information from a patient to be monitored. The pressure sensing device comprising an exterior housing accommodating a snore detection circuit which processes information and outputs a signal indicative; an airflow detection circuit which processes information and outputs a signal indicative thereof; and an internal test circuit for testing an integrity of the airflow and snore detection circuits prior to use of the pressure sensing device to ensure that both circuits are operational. An input port for pressure sensing device extends from the housing of the pressure sensing device so as to space a connector, for the cannula, a sufficient distance away from the bottom surface whereby the bottom surface will always remain flush with and in constant and continuous intimate contact with a support surface for the pressure sensing device.