Abstract: A method of and apparatus for producing a controlled pressure level in a respirator for human patients which is equipped with a tracheal tube 3 connected to the respirator and connectable to the trachea, comprises producing an oscillatory gas stream by means of two opposite gas jets in an attachment tube 4 which has two end openings. By controlling the pressure and/or frequency of the gas jets, a varying pressure level propagating into the tracheal tube is modulated onto the gas stream. The respirator for carrying out the method comprises two gas jet pipes 20, 21 having nozzle tips 24, 25 of which one discharges or points within the attachment tube 4 substantially in the direction of the tracheal tube 3 and the other substantially in the opposite direction.