Sabine’s formula persists despite relying on an unattainable diffusion ideal

Evidence

The diffusion principle is an idealization that is never perfectly attained. Some rooms are of a shape that discourages diffusion of the sound, such as a rectangular room with flat walls. The sound may not have time to randomize and become diffuse. The corrections are especially important for very absorbent surfaces, where a large fraction of the sound energy is removed at each bounce. (The exponential does not apply if too much is lost at each bounce). Many improvements to Sabine’s formula have been made over the years to correct for these effects, but the Sabine formula remains in use by the acoustical profession, with awareness of its weaknesses. — Eric J. Heller, Why You Hear What You Hear- An…, 2491

Categorization

• XREF: A useful-model-with-known-faults pattern — mirrors how the law merchant model and other idealized frameworks stay in use despite limits.