Auxiliary device for assisting in singling or separating sheets in an upper region of a sheet pile provided for single-sheet transport in a sheet transport direction within a sheet processing machine, a respective top sheet of the sheet pile being removable therefrom at a given time by at least one singling or separating device including at least one sheet trailing edge blasting or blowing device for feeding the sheet to the sheet processing machine, includes at least one feeler rod disposed at a location transverse to the sheet transport direction for measuring the height of the sheet pile, and respective fanning or loosening blowers disposed laterally of the sheet pile upstream of the feeler rod, as viewed in the sheet transport direction.
