Numerous acousticians investigated correlation between subjective judgement of reverberation and objective criteria in concert halls. It is widely believed that the initial part of the impulse response is the most important criterium in the evaluation of reverberation length, most often referred to as the EDT value, having the best correlation with the perceived reverberation length. This presentation shows the results of an experiment on the perception of reverberation length in rooms with an installed Active Acoustic Enhancement System (AAES). Most of the impulse responses recorded in concert halls with an AAES switched on, is not linear, but has a so-called double-slope shape, which distinguishes it from most impulse responses recorded in rooms without this system. Therefore, it is important to verify the relationship between the subjective evaluation of reverberation length and its objective measures using the EDT, RT10, RT20 and RT30 parameters. The experiment analysed the perception of reverberation length for both temporal and running reverberation. The results obtained show a difference in the evaluation of the length of temporal reverberation and running reverberation and suggest that not only the first part of the impulse response is important in the evaluation of reverberation length.