The invention relates to a method for operating an ultrasonic sensor, in which multiple measuring cycles are run in succession. In each measuring cycle: an electro-acoustic transducer of said ultrasonic sensor is excited, by means of an exciting pulse, to mechanically vibrate, as a result of which a measurement signal is sent by the transducer; an echo signal is received by the transducer; and anitem of object information is determined from said echo signal. The frequency response curve of the exciting pulse is differentiated, according to the invention, into measuring cycles run in temporalsuccession, wherein the frequency response curve of an exciting pulse is selected, in each measuring cycle, from a group of predetermined frequency response curves, either at random or according to apredetermined sequence.