This work aims to study the vibro-acoustic behavior of wood floors. The ultimategoal is to be able to better take into account the low frequencies (20 Hz-100 Hz) inthe acoustic global indices used in building acoustics and thus, to better adapt themto light wood constructions sensitive to this range of frequencies. By modifying thearrangement of wooden joists, two constructive principles were considered in orderto observe the effect of rigidity. The natural frequencies and the modal deformationsof these wood floors were then estimated from the frequency response functionsresulting from hammer impact measurements. A finite element modeling of thesefloors was then carried out by having previously estimated the input parameters(Young's modulus) from the measurements made on each of the structural elementsof these floors (joists, plates) in condition free movement. A parametric study wasthen carried out in order to better understand the influence of these constructiveprinciples.