A HFCWO system includes an air pulse generator having a blower inlet in communication with a blower and an air port in communication with an inflatable garment. The air pulse generator includes a housing and an air pulse assembly coupled to the housing. The air pulse assembly has at least one diaphragm, at least one driver operable to move the at least one diaphragm and at least one spring arranged to bias the at least one diaphragm away from a portion of the housing.