A-weighted dB values misrepresent perceived loudness for complex sounds.

Evidence

Using the data plotted in Fig. 8.2 together with those plotted in Fig. 8.1, the equal-loudness contours of the diffuse sound field can easily be constructed. Equal-loudness contours for sinusoidal tones or narrow-band noises indicate the interesting dependence of loudness on frequency. However, loudness depends on many more variables such as bandwidth, frequency content, and duration. Consequently, it is too simple to approximate loudness level by a single weighting such as the A-weight.ed sound pressure level. Because A-weighting has a frequency dependence that corresponds to that of the equal-loudness contours at low levels, A-weighted sound pressure level approximates loudness level only for sinusoidal tones or narrow-band noises at lower levels. Therefore, dB(A)-values of noises or complex tones, or combinations of both, are misleading when used as indications of subjectively perceived loudness. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1176

Categorization

• SEED: Article angle: why ‘dB(A)’ on every product spec sheet fails to predict how loud things actually feel.
• SHARE: Great tidbit for an acoustics-engineer or audio-producer friend who quotes dB(A) as if it were loudness.
• corroborated: 2 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1176
• XREF: connects to: A-weighted decibels are a rough practical approximation of perceived loudness — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 633; A-weighted sound pressure level misrepresents the loudness of broadband noises; Equal-loudness-contour weighting schemes failed as loudness meters (+17 more)

Broader Connections

• A-weighted decibels are a rough practical approximation of perceived loudness #qualifies (0.95) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 633
• A-weighted sound pressure level misrepresents the loudness of broadband noises #exemplifies (0.95)
• A-weighting can miss dominant low-frequency energy in broadband sounds #exemplifies (0.90)
• Equal-loudness-contour weighting schemes failed as loudness meters #corroborates (0.85)
• Perceived loudness does not map one-to-one onto acoustic amplitude #expands (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 616
• Perceived loudness and physical sound intensity follow different, non-intuitive mathematical scales #expands (0.85) — George Michelsen Foy, Zero Decibels, 53
• A-weighted sound power exaggerates perceived loudness differences in marketing #exemplifies (0.80) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1778
• Loudness scales with frequency squared, requiring large amplitude at low frequencies #expands (0.80)
• Loudness perception is essentially logarithmic #expands (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 611
• ISO standardized loudness-based noise metrics because A-weighting proved inadequate #contradicts (0.70)