A guide vane segment for a turbomachine stage that has an inner ring segment (10) and a plurality of guide vanes (20) that are configured on the inner ring segment; a detuning region (V) of the inner ring segment extending in each case from a trailing edge (21) of at least one guide vane (20), in particular of at least 50% of the guide vanes (50), axially toward a leading edge (22) of the guide vane (20) over at most 50% of a width (B) of the inner ring segment (10) and/or at most 5 mm and/or circumferentially on both sides, in each case over at most 25% of a spacing (A) between adjacent guide vanes (20), at and/or in which at least one cavity (112) is configured which contains at least one impulse element (100) with clearance of motion for providing impact contacts.