Cleaning apparatus with flow deflection element with mode filter

A cleaning apparatus, comprising at least one noise source and an air guidance device having at least one flow deflection element, wherein the at least one flow deflection element has a first duct arm, having a first duct arm depth, and a second duct arm, having a second duct arm depth, wherein the first duct arm depth and the second duct arm depth are equal to one another, wherein the second duct arm is oriented transversely to the first duct arm at a right angle, and wherein, during operation of the cleaning apparatus, there is sound propagation from the first duct arm to the second duct arm, and at a transition region from the first duct arm to the second duct arm transverse modes of sound propagation arise, wherein a mode filter device for transverse modes of sound propagation is arranged at the at least one flow deflection element, having at least one mode filter that is positioned at the second duct arm, such that a spacing of the at least one mode filter which is arranged at the second duct arm is at least 0.1 times a first width of the first duct arm in a first width direction or a second width of the second duct arm in a second width direction, wherein the spacing is parallel to a first width direction and relates to a side of the first duct arm that lies at an internal corner region of the at least one flow deflection element.