Loudness scales with frequency squared, requiring large amplitude at low frequencies

Evidence

Loudness is the perceptual correlate of sound level. But it is also dependent on frequency, incident angle, the duration of the signal and its temporal envelope. It is one of many psychoacoustic relationships that defy simple descriptions. Yet, one must start somewhere, and so most investigators focused on pure tones in acoustically simple circumstances, like headphone or anechoic listening. — Toole, Floyd E, Sound reproduction- the acoustics and…, 903 (#expands, via linked claim)

Loudness is mainly the perceptual correlate of sound intensity, which is usually expressed in dB SPL as sound pressure level on a logarithmic scale. However, loudness judgments are also affected by several other variables, including physical sound parameters like e.g. duration, spectral content and temporal modulation as well many more acoustic and non-acoustic factors, including the particular task or context and personal factors like the individual hearing status (Florentine et al. — Dijk, Pim van, Physiology, Psychoacoustics and…, 2610 (#expands, via linked claim)

In order to have a better, yet relatively simple, measure of the perceived level of sound, the concept of sound level is defined as a measure that is weighted with frequency so that the level roughly approximates the frequency sensitivity of hearing. Four different weighting curves are defined: A, B, C, and D, as shown in Figure 9.3. The A-weighted sound level is commonly used in noise measurements to characterize the perceived level and the risk of hearing loss. The A weighting slightly emphasizes the levels at mid frequencies and attenuates them at low and high frequencies. When the weighting curve is compared with the inverted equal-loudness curves, it is easy to see that the A weighting is just a very rough estimate. Technical simplicity and extensive use in practice are its advantages. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 988 (#qualifies, via linked claim)

Categorization

• XREF: connects to: A-weighted dB values misrepresent perceived loudness for complex sounds. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1176; Loud audible tones require only tiny surface velocities of millimeters per second; Loudness growth with intensity requires experimental quantification, not intuition (+7 more)

Related

• Loudness depends on frequency, angle, duration, and envelope, not just level (similarity 0.94)
• Loudness, measured in sones, depends inherently on frequency content (similarity 0.93)
• Loudness depends on more than physical sound intensity alone (similarity 0.92)
• Loudness is perceptual and unmeasurable directly, while intensity is acoustic and directly quantifiable (similarity 0.92)
• Loudness perception is logarithmic, which is why decibel scales fit hearing so well. (similarity 0.90)
• Perceived loudness does not map one-to-one onto acoustic amplitude (similarity 0.89)
• Loudness meters use frequency weightings as a compromise because ear response varies with level (similarity 0.89)
• A-weighting is recommended for all sound levels despite fitting low levels best (similarity 0.88)
• A-weighted decibels are a rough practical approximation of perceived loudness (similarity 0.88)
• Loudness is measured by listeners assigning numbers relative to a reference sound. (similarity 0.88)
• Loudness growth with intensity requires experimental quantification, not intuition (similarity 0.88)
• Loudness perception is essentially logarithmic (similarity 0.88)
• Sound intensity level and sound pressure level are roughly equivalent (similarity 0.88)
• A-weighted dB values misrepresent perceived loudness for complex sounds. (similarity 0.88)
• The loudness function approaches a vertical asymptote at the 3 dB threshold in quiet (similarity 0.87)

Broader Connections

• Loudness depends on frequency, angle, duration, and envelope, not just level #expands (0.85) — Toole, Floyd E, Sound reproduction- the acoustics and…, 903
• Loudness depends on more than physical sound intensity alone #expands (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 2610
• A-weighted decibels are a rough practical approximation of perceived loudness #qualifies (0.72) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 988
• Loudness growth with intensity requires experimental quantification, not intuition #qualifies (0.70)