Sound absorption coefficients vary dramatically by surface material and frequency

Evidence

Plaster on lath 0.14 0.10 0.06 0.05 0.04 0.03 Carpet on concrete 0.02 0.06 0.14 0.37 0.60 0.65 Floor (wood joist) 0.15 0.11 0.10 0.07 0.06 0.07 Painted plaster 0.01 0.01 0.02 0.02 0.02 0.02 Walls (1/2-inch plasterboard) Windows (float glass) 0. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1885

Categorization

• XREF: Concrete carpet numbers confirm the classic hard-floor-absorbs-low, soft-carpet-absorbs-high rule from the background reading on room acoustics. — connects to: Snow exceeds other natural surfaces in sound absorption by a large margin. — Donald G. Albert and John A. Orcutt, Acoustic Pulse Propagation Above…, 6; Snow is the most sound-absorbent natural ground cover — Donald G. Albert, Acoustic Waveform Inversion with…, 5