Strutt|Building Acoustics|Floating Floor Correction inserts the improvement (insertion loss) to the airborne transmission loss of a floor/ceiling combination from the addition of a structurally-isolated floating floor above.
The insertion loss values are given for the case of a 100 mm airgap for three floating slab thicknesses: 75 mm, 100 mm or 125 mm.
Reference: Miller, L.N. Noise Control for Buildings and Manufacturing Plants, Table 5-20