The sound propagation within a room depends on the refl ection, absorption and spreading of sound waves on all surfaces and objects in the room. The most important parameter describing the room acoustics is the reverberation time. The reverberation time describes, how long time it takes for a sound to decay 60 dB after the source has stopped.
Depending on the measurement procedure, the reverberation time is called T20 (measured decay from -5 dB to -25 dB and extrapolated to 60 dB decay), T30 (measured from -5 dB to -35 dB and extrapolated) or EDT (Early Decay Time, the initial 10 dB decay extrapolated to 60 dB).
The reverberation time for a room can be calculated according to Sabine’s reverberation equation (Wallace C. Sabine, founder of modern acoustics; 1868-1919)
Calculation of reverberation time T:
The calculation has to be done for every octave band.
Reverberation is a very important factor for the quality or wellness of the sound, but within marine regulations this is an issue not dealt with.
Examples from building regulations seen below:
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