Surface absorption weakens early reflections below inverse-square-law predictions

Evidence

The amount of sound energy available for contribution to the reverberant field is also a function of the absorption, because if there is a large amount of absorption, there will be less direct sound reflected off a surface to contribute to the reverberant field-remember that before the first reflection, the sound is direct sound. The amount of sound energy available to contribute to the reverberant field is therefore proportional to the residual energy left after the first reflection, Reverberant level is that which allows input to equal output FIGURE 6. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1763 (#corroborates, via linked claim)

Categorization

• XREF: connects to: Anti-reflection coatings work by breaking impedance mismatch into graded steps; Total surface area determines a material’s acoustic dominance more than its absorption coefficient alone; Reflected sound obeys an inverse square law in addition to surface absorption losses (+5 more)

Broader Connections

• Reflected sound obeys an inverse square law in addition to surface absorption losses #qualifies (0.85)
• Higher absorption reduces the first-reflection energy that feeds the reverberant field #corroborates (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1763
• Absorbing first reflections cascades to attenuate the whole reflected sound field #corroborates (0.80)
• Reverberation time depends on both surface absorption and time between reflections #expands (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1824
• Absorption coefficients reduce reflected intensity by their proportion #expands (0.75)
• Absorption at each reflection governs how fast reverberation decays #expands (0.70) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1743