Reverberation decay functions for narrow bands obtained from filtered time-windowed room impulse responses

This study introduces a method to obtain the reverberation decay functions for narrow bands from the filtered time-windowed broadband room impulse responses. The method corresponds to the free decay process of the band-pass sound energy. The filtering process is independent of the band-pass filter phase responses and it reduces the filtering influence on the decay rates. It places no limit on the permissible product BT of the bandwidth B and the reverberation time T when evaluating the decay rates of the obtained decay functions.