One-third octave representation of the obtained reverberation times T₂₀ by using a noise and impulse source including their standard deviation. The T₂₀ values are shown here because the signal-to-noise ratio was too small, so that a 60 dB drop in the sound pressure level was not observed (the T₂₀ values were determined when the decay curve first reaches the values 5 dB and 25 dB below the initial level and then extrapolated to a 60 dB decay to approximate the T₆₀ values).