Sound measurement must be frequency-weighted because ears are not uniformly sensitive

Evidence

Just as the notation of music is now being replaced by the record player, the tape recorder is pushing the physical study of acoustics into the human area of psychoacoustics. And for general field work in measuring the intensity of sound, the flat response of the sound level meter (the so-called C scale) has given way to the contoured A scale, weighted along the lines of the equal loudness contours of the human ear. Similarly, the numerous refinements in measuring aircraft noise in recent years have tended more and more to take human response into consideration. Thus EPNdB (Effective Perceived Noise in Decibels) takes into account the particular tone components of aircraft as well as the duration of the noise, while NNI (Noise and Number Index) uses the EPNdB as a basis and additionally calculates the number of aircraft per day (or night) as a key annoyance factor. — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 440 (#expands, via linked claim)

In the frequency range between 2 and 5 kHz almost every subject with normal hearing exhibits a very sensitive range in which very small sound pressure levels below 0 dB are reached. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 168 (#exemplifies, via linked claim)

Categorization

• XREF: connects to: Loudness meters use frequency weightings as a compromise because ear response varies with level; Human hearing requires far more SPL to detect low-frequency tones than mid-range ones; Ear frequency response varies with amplitude, especially at low frequencies. (+5 more)

Related

• Loudness meters use frequency weightings as a compromise because ear response varies with level (similarity 0.90)
• Sound measurement has shifted from flat physical scales toward human-perception-weighted scales (similarity 0.90)
• A-weighting is recommended for all sound levels despite fitting low levels best (similarity 0.88)
• No single frequency-weighting can accurately meter loudness at all levels (similarity 0.87)
• The mel scale is largely discredited yet remains used in speech and acoustics (similarity 0.86)
• Perceived loudness meters must weight frequencies as a compromise across sound levels. (similarity 0.85)
• Equal-loudness-contour weighting schemes failed as loudness meters (similarity 0.85)
• Ear sensitivity depends jointly on frequency and on sound level (similarity 0.85)
• Sound reproduction quality depends on both physical acoustics and human perception (similarity 0.85)
• Loudness scales with frequency squared, requiring large amplitude at low frequencies (similarity 0.84)
• A-weighted decibels are a rough practical approximation of perceived loudness (similarity 0.83)
• Human hearing requires far more SPL to detect low-frequency tones than mid-range ones (similarity 0.83)
• A-weighted decibels better predict hearing damage than unweighted sound pressure level. (similarity 0.82)
• Loudness depends on frequency, angle, duration, and envelope, not just level (similarity 0.82)
• A-weighting can miss dominant low-frequency energy in broadband sounds (similarity 0.82)

Broader Connections

• Loudness meters use frequency weightings as a compromise because ear response varies with level #corroborates (0.95)
• Sound measurement has shifted from flat physical scales toward human-perception-weighted scales #expands (0.90) — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 440
• Human hearing requires far more SPL to detect low-frequency tones than mid-range ones #exemplifies (0.85)
• Ear frequency response varies with amplitude, especially at low frequencies. #qualifies (0.85)
• Normal hearing is most sensitive near 2 to 5 kHz #exemplifies (0.85) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 168
• A-weighted sound pressure level misrepresents the loudness of broadband noises #complicates (0.80)
• Physical frequency is the wrong scale for describing inner-ear effects #expands (0.75)