A device for providing a high frequency ventilation to a patient that includes a pressure generating system that delivers a flow of breathing gas to the patient, where the flow has a first and second positive pressure levels that alternate with one another in a plurality of cycles in the flow so as to have a frequency and an amplitude. The flow generates a mean airway pressure. A controller, coupled to the pressure generating system, is configured to make a determination, as to a spontaneous breathing, or an attempt, by the patient, or a change in a user settings by a user, and in response adjusts the mean airway pressure, modulates the frequency and a duty cycle of the flow, or modulates a level of the flow and the amplitude of the flow, or two or more flows.