The study gives the results of the measurements of the reverberation time in 11,687 rooms, of which 11,457 are furnished (8,246 bedrooms, 3,211 living rooms), and 230 unfurnished. All the rooms have thick walls and ceilings and a heavy floor covering. The reverberation times measured are quite similar in bedrooms and living rooms within the same size range, and decrease fairly uniformly as the frequency increases. Moreover, in each frequency band the greater the volume of the room, the greater the reverberation time. The results of this extensive fieldwork allow us to predict accurately the reverberation time in these kinds of spaces as a function of their size and the frequency. These data may be useful for improving the accuracy of calculation models to estimate the reverberation time of enclosed spaces. The equivalent sound absorption area of these rooms was also calculated.