Editing Reverberation (section)

=== Eyring equation ===
Eyring's reverberation time equation was proposed by [[Carl F. Eyring]] of [[Bell Labs]] in 1930.<ref>{{cite journal |last1=Eyring |first1=Carl F. |title=Reverberation Time in "Dead" Rooms  |journal=The Journal of the Acoustical Society of America |year=1930 |volume=1 |issue=2A |pages=217–241 |doi=10.1121/1.1915175 |bibcode=1930ASAJ....1..217E |doi-access= }}</ref>  This equation aims to better estimate the reverberation time in small rooms with relatively large quantities of sound absorption, identified by Eyring as "dead" rooms.  These rooms tend to have lower reverberation times than larger, more acoustically live rooms.  Eyring's equation is similar in form to Sabine's equation, but includes modifications to [[natural logarithm|logarithmically]] scale the [[absorption (acoustics)|absorption]] term. The units and variables within the equation are the same as those defined for Sabine's equation.  The Eyring reverberation time is given by the equation:

:<math>T_{60} \approx -0.161\ \frac{V}{S \ln (1-a)}</math>.

Eyring's equation was developed from first principles using an image source model of sound reflection, as opposed to Sabine's [[empirical]] approach.  The experimental results obtained by Sabine generally agree with Eyring's equation since the two formulae become identical for very live rooms, the type in which Sabine worked. However, Eyring's equation becomes more valid for smaller rooms with large quantities of absorption.  As a result, the Eyring equation is often implemented to estimate the reverberation time in [[recording studio]] control rooms or other critical listening environments with high quantities of sound absorption.  The Sabine equation tends to over-predict reverberation time for small rooms with high amounts of absorption.  For this reason, reverberation time calculators available for smaller recording studio environments, such as [[home recording]] studios, often utilize Eyring's equation.