In the field of room acoustics, it is well known that reverberation can be character-1 ized statistically in a particular region of the time-frequency domain (after the tran-2 sition time and above Schroeder's frequency). Since the 1950s, various formulas have 3 been established, focusing on particular aspects of reverberation: exponential decay 4 over time, correlations between frequencies, correlations between sensors at each fre-5 quency, and time-frequency distribution. In this paper, we introduce a stochastic 6 reverberation model, that permits us to retrieve all these well-known results within 7 a common mathematical framework. To the best of our knowledge, this is the first 8 time that such a unification work is presented. The benefits are multiple: several 9 formulas generalizing the classical results are established, that jointly characterize 10 the spatial, temporal and spectral properties of late reverberation. 11