Ultrasonic sensor comprising a sound transducer and a horn, wherein the sound transducer is arranged at a base opening of the horn, wherein the horn has at least three wall segments (51, 52, 53) with respect to a sectional plane perpendicular to a membrane of the sound transducer, wherein a first wall segment and a second wall segment adjoin the sound transducer and a third wall segment is arranged at the end of the first wall segment remote from the sound transducer and is angled with respect to the first wall segment in the direction of the sound transducer, wherein the angle between the first wall segment and the third wall segment is chosen such that the third wall segment runs substantially parallel to the radiating direction of the sound transducer, wherein the first, second and third wall segments are designed in such a form that they each appear as a straight line with respect to the sectional plane, wherein the transitions between these straight lines are shaped in an angular form, characterized in that the form of the horn is designed asymmetrically in such a way that, during the radiation of sound from the sound transducer, a first sound lobe is produced as a result of the direct radiation of sound from the sound transducer and the sound reflected at the first wall segment and that, during the radiation of sound from the sound transducer, a second sound lobe is produced as a result of interference between the direct sound and sound scattered at edges of the horn, wherein the radiating directions of the first sound lobe and the second sound lobe are different, wherein, with respect to the sectional plane, the first wall segment forms an angle in relation to a side of the sound transducer facing in the radiating direction in the range of 180° and 90°, and the second wall segment forms an angle in relation to the side of the sound transducer facing in the radiating direction in the range of 180° and 270°. wherein the angle between the first wall segment and the third wall segment is chosen such that the third wall segment runs substantially parallel to the radiating direction of the sound transducer, wherein the first, second and third wall segments are designed in such a form that they each appear as a straight line with respect to the sectional plane, wherein the transitions between these straight lines are shaped in an angular form, characterized in that the form of the horn is designed asymmetrically in such a way that, during the radiation of sound from the sound transducer, a first sound lobe is produced as a result of the direct radiation of sound from the sound transducer and the sound reflected at the first wall segment and that, during the radiation of sound from the sound transducer, a second sound lobe is produced as a result of interference between the direct sound and sound scattered at edges of the horn, wherein the radiating directions of the first sound lobe and the second sound lobe are different, wherein, with respect to the sectional plane, the first wall segment forms an angle in relation to a side of the sound transducer facing in the radiating direction in the range of 180° and 90°, and the second wall segment forms an angle in relation to the side of the sound transducer facing in the radiating direction in the range of 180° and 270°.