Loudness measures can reveal real improvements A-weighting misses entirely

Evidence

The relative loudness reduction from 27.5 to 18.3 and finally to 13.5 sone (GF) corresponds to factors of 1.50 and 1.36. These ratios indicate that the second step was also quite effective, although the reduction of Aweighted SPL was 1:3 dB(A) in the first step and only 4 dB(A) in the second. The workers in the factory. however, were very pleased with the second step. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1763

Categorization

• XREF: Connects to the broader theme in the reader’s knowledge base of how A-weighted SPL inadequately predicts perceived annoyance versus true loudness models. — connects to: C-weighting captures low frequencies better at high sound pressures — David Howard, Jamie Angus, coustics and Psychoacoustics, 624