Reverberation time is defined
as the time it takes for a white noise signal to be attenuated by 60 dB SPL after the signal is
As mentioned in the article about loudspeaker stereo setups,
domestic living rooms in europe have a reverberation time of 0.4 - 0.7 seconds according to IEC.
That means that you should aim for this value in the listening environment in which you playback music.
I have designed some wav files where different reverberation times are demonstrated using a white noise signal
The white noise signal exploits the full 16 bit dynamic range of PCM so be CAREFUL with the volume level
when you play it !