Audio hero - W.C. Sabine
We have Wallace Clement Sabine to thank for the modern science of acoustics. Although the ancients found out a thing or two - such as the amphitheater - in a 'suck it and see' kind of way, Sabine was the first to apply the process of science to acoustics.
As far back as 1898 - before anything that we would now recognize as sound engineering was invented - Sabine sought to link the physical characteristics of a room or auditorium with its perceived sound quality.
Sabine hit upon reverberation time as the principal defining factor and took measurements of the Fogg lecture room at Harvard. He came up with an empirical formula that does indeed work very well. (An empirical formula is a formula worked out from known data, not developed from first principles). The formula is this...
RT60 = 0.16 x V / A
Where RT60 is the time taken for a sound to decay to one millionth of its original intensity (or by 60 dB, in terms we would use today); V is the volume of the auditorium in cubic meters, and A is the absorption in sabins. The unit of the sabin is the absorption that is equivalent to one square meter of a completely absorbent surface (the 'open window unit'). What happened to the 'e' in sabin, history does not record.
The amazing thing is that this simple formula works very well to a first approximation. Better formulae have been developed from his work, and from first principles, but for Sabine to do this over 100 years ago was a major step forward, on a par with Edison's invention of the phonograph, for sure.