A pneumatic actuator (4b), in particular for use in a pressure wave generator (1) comprises: a first piston surface (91) which acts counter to a gaseous working medium in a first volume (41), wherein a pressure in the first volume (41) effects an actuator force in a first direction upon the first piston surface (91); a second piston surface (92) which acts counter to the working medium in a second volume (42), wherein a pressure in the second volume (42) effects an actuator force in a second direction opposite to the first direction, upon the second piston surface (92); a throttle between the first volume (41) and the second volume (42); an inlet/outlet opening (45) of the first volume (41) for bringing the working medium into and discharging it out of, the first volume; wherein the first piston surface (91) is larger than the second piston surface (92).