In this lecture, different well-established methods of reverberation time measurement will be compared. This includes the standardized methods (EN ISO 3382:2000), namely the impulse response measured with pink noise, exponential sweep, MLS, but also additional methods like pistol shots of different calibers, balloon bursts, gated external pink noise, and the B&K filtered burst method. In order to make the comparison, the measurements were performed in four acoustically very different spaces - a rather small and well-damped listening room, a much bigger damped drama theatre, a rather reverberant atrium, and a large and very reverberant shoebox-shaped room. Although the relevant standards state that impulse-like sources should be avoided due to the lack of measurement repeatability, their use has proved to be necessary due to inability of conventional omni-directional loudspeakers to provide adequate sound pressure levels at the low end of the frequency range of interest. Therefore, the peak sound pressure levels and the amount of low frequency content of following sources were measured: pistol shots, firecrackers with different amount of explosive compound and balloon bursts. Special attention has been given to measurements of reverberation time in small and rather reverberant shoe-box type room, in order to determine the spatial distribution of reverberation time with respect to the formation of standing waves in the room itself.