A-weighting’s underestimate of low-frequency energy explains about four dB of the railway bonus.

Evidence

As an explanation for the railway-bonus at least two hypotheses can be put forward. From an engineering point of view, it can be argued that road traffic noise shows more pronounced lowfrequency components which are underestimated by A-weighting. Hence, at same LAeq, road-traffic is perceived as louder than rail-traffic. By and large, the problems of A-weighted levels for sounds with strong low-frequency components could account for some four dB of the railway-bonus. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1813

Categorization

• XREF: Connects to the reader’s established interest in A-weighting limitations, tying to the soundscape and noise chapters already read.