A respiratory treatment device comprising at least one chamber, a chamber inlet configured to receive exhaled air into the at least one chamber, at least one chamber outlet configured to permit exhaled air to exit the at least one chamber, and an exhalation flow path defined between the chamber inlet and the at least one chamber outlet. A restrictor member positioned in the exhalation flow path is moveable between a closed position, where a flow of exhaled air along the exhalation flow path is restricted, and an open position, where the flow of exhaled air along the exhalation flow path is less restricted. A vane in fluid communication with the exhalation flow path is operatively connected to the restrictor member and is configured to reciprocate between a first position and a second position in response to the flow of exhaled air along the exhalation flow path.
