ABSTRACT
In 1898, Wallace Sabine, a physicist at Harvard University, developed a formula that defined the relationships between the volume of a room (10, the total surface area (S), the absorption coefficient of the materials in the room, (α), and the time it will take for a sound to decay to one millionth of its original intensity RT 60. The formula https://www.w3.org/1998/Math/MathML"> R T 60 = .161 V S α https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780240813400/3c9857d1-c358-4a3b-b012-8dec9df32c71/content/math21_233_1_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (use 0.049 as constant for feet) that he developed purely by observation is still used today. Over the years there have been developed a few different forms of the basic equation that may yield more accurate results in certain conditions. In his paper describing this equation he includes a comment that is remarkable in its prophetic nature. In a section of the paper dealing with terminology he addresses the difference between resonance and reverberation. He says, “In scientific literature the term resonance has received a very definite and precise application to the phenomenon, where ever it may occur, of the growth of a vibratory motion of an elastic body under periodic forces timed to its natural rates of vibration. A word having this significance is necessary; and it is very desirable that the term should not, even popularly, by meaning many things, cease to mean anything thing exactly” 1
