Abstract: Steel components have generally poor acoustic performance compared to concrete ones. This paper introduces a new type of damping steel into building structures, which offers excellent acoustic performance and good mechanical properties, achieving structural and functional integration. Based on the measured damping parameters of materials, ten numerical models for airborne sound insulation of air-spaced slabs were established, showing that the damping steel outperforms traditional steel in sound insulation, with the sound transmission losing about 7 dB higher. The influence of panel thickness, core tube height, and core tube thickness was insignificant. Four models for airborne sound insulation of steel-concrete composite slabs were established, showing that the steel type has minimal influence on the airborne sound insulation, while thickening the concrete can improve it significantly. Another ten models for impact sound reduction of air-spaced slabs show that the slabs using damping steel have better performance against impact sound compared to traditional steel, with the sound pressure level about 2.5 dB lower. Overall, heavier air-spaced slabs provide better sound reduction performance against impact sound.