The sabin (or more precisely the square foot sabin) is a unit of

sound absorption Acoustic absorption refers to the process by which a material, structure, or object takes in sound energy when sound waves are encountered, as opposed to reflecting the energy. Part of the absorbed energy is transformed into heat and part is tran ...

, used for expressing the total effective absorption for the interior of a room. Sound absorption can be expressed in terms of the percentage of energy absorbed compared with the percentage reflected. It can also be expressed as a coefficient, with a value of 1.00 representing a material which absorbs 100% of the energy, and a value of 0.00 meaning all the sound is reflected. The concept of a unit for absorption was first suggested by American

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...

Wallace Clement Sabine Wallace Clement Sabine (June 13, 1868 – January 10, 1919) was an American physicist who founded the field of architectural acoustics. Sabine was the architectural acoustician of Boston's Symphony Hall, widely considered one of the two or thre ...

, the founder of the field of

architectural acoustics Architectural acoustics (also known as building acoustics) is the science and engineering of achieving a good sound within a building and is a branch of acoustical engineering. The first application of modern scientific methods to architectura ...

. He defined the "open-window unit" as the absorption of of open window. The unit was renamed the sabin after Sabine, and it is now defined as "the absorption due to unit area of a totally absorbent surface". Sabins may be calculated with either

imperial Imperial is that which relates to an empire, emperor, or imperialism. Imperial or The Imperial may also refer to: Places United States * Imperial, California * Imperial, Missouri * Imperial, Nebraska * Imperial, Pennsylvania * Imperial, Texa ...

metric Metric or metrical may refer to: * Metric system, an internationally adopted decimal system of measurement * An adjective indicating relation to measurement in general, or a noun describing a specific type of measurement Mathematics In mathem ...

units. One square foot of 100% absorbing material has a value of one imperial sabin, and 1 square metre of 100% absorbing material has a value of one metric sabin. The total absorption ''A'' in metric sabins for a room containing many types of surface is given by :

A = S_1 \alpha_1 + S_2 \alpha_2 + \ldots + S_n \alpha_n = \sum S_i \alpha_i ,

where ''S''₁, ''S''₂, ..., ''S''_''n'' are the areas of the surfaces in the room (m²) and ''α''₁, ''α''₂, ..., ''α''_n are the

absorption coefficient The linear attenuation coefficient, attenuation coefficient, or narrow-beam attenuation coefficient characterizes how easily a volume of material can be penetrated by a beam of light, sound, particles, or other energy or matter. A coefficient valu ...

s of the surfaces. Sabins are used in calculating the

reverberation time Reverberation (also known as reverb), in acoustics, is a persistence of sound, after a sound is produced. Reverberation is created when a sound or signal is reflected causing numerous reflections to build up and then decay as the sound is abso ...

of concert halls,

lecture theatre A lecture hall (or lecture theatre) is a large room used for instruction, typically at a college or university. Unlike a traditional classroom with a capacity normally between one and fifty, the capacity of lecture halls is usually measured in ...

s, and recording studios.

References

Sources

* * {{cite book , last1=Moore , first1=John Edwin , title=Design for Good Acoustics and Noise Control , date=1979 , publisher=Macmillan , location=London , isbn=978-03332-4-293-3 , url=https://www.google.co.uk/books/edition/Design_for_Good_Acoustics_and_Noise_Cont/RD5dDwAAQBAJ?hl=en&gbpv=0

External links

Understanding sabins
from NetWell Noise Control Units of measurement Sound measurements