Total surface area can outweigh absorption efficiency in controlling room reverberation

Evidence

What is the 60 dB reverberation time (T60) of a living room as a function of frequency whose surface area is 75 m2 and whose volume is 42 m3? The floor is carpet on concrete, the ceiling is plaster on lath, and both have an area of 16.8 m2. There are 6 m2 of windows and the rest of the surfaces are painted plaster on brick; ignore the effect of the door. Using the data in Table 6.1, set up a spreadsheet or table, as shown in Table 6.2, and calculate the equivalent open window area for each surface as a function of frequency. Having done that add up the individual surface contributions for each frequency band and apply Equation 6.20 to the result in order to calculate the reverberation time. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1929

Categorization

• corroborated: 2 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 1929
• XREF: connects to: Physical sound absorption can be strong enough to measurably alter room reverberation; Reverberation time depends on room volume and surface area, not absorption alone. — Eric J. Heller, Why You Hear What You Hear- An…, 2476; Total surface area determines a material’s acoustic dominance more than its absorption coefficient alone (+7 more)