Loudness is the summed specific loudness across critical-band rates, not the raw spectral level

Evidence

The first effect is that the ear seems to lump all the energy within a critical band together and treat it as one item of sound. So when all the sound energy is concentrated within a critical band, the loudness is proportional to the total intensity of the sound within the critical band. … As the ear is sensitive to sound pressures, the sound intensity is proportional to the square of the sound pressures, as discussed in Chapter 1. Because the acoustic intensity of the sound is also proportional to the sum of the squared pressure, the loudness of a sound within a critical band is independent of the number of frequency components so long as their total acoustic intensity is constant. When the frequency components of the sound extend beyond a critical band, an additional effect occurs due to the presence of components in other critical bands. In this case, more than one critical band is contributing to the perception of loudness, and the brain appears to add the individual critical band responses together. The effect is to increase the perceived loudness of the sound even though the total acoustic intensity is unchanged. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 665 (#expands, via linked claim)

The loudest sounds, when presented at equal SPLs, are in the 2 to 6 kHz range. • Loudness depends on stimulus bandwidth: For bandwidths greater than a critical band, loudness increases with increasing bandwidth, a phenomenon called spectral loudness summation. A sound can be loud because of a high sound level or because it has a broad bandwidth. • Weber’s law predicts that the just detectable amount of intensity is proportional to the intensity of the sound (DI/I = k). Weber’s law holds for noise at moderate-to-high levels but not for low levels or for tones. Tones exhibit a near miss, in which DI/I or DL decreases with increasing intensity. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 868 (#expands, via linked claim)

Categorization

• XREF: connects to: Loudness rises once noise bandwidth exceeds the critical band at constant SPL.; Loudness stays constant below critical bandwidth then grows beyond it — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1034; Total loudness is the integral of specific loudness over critical-band rate — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1250 (+8 more)

Related

• Loudness grows when sound energy spills beyond a single critical band (similarity 0.97)
• Wider bandwidth increases perceived loudness at equal sound pressure (similarity 0.93)
• Spreading a sound’s energy across more critical bands increases perceived loudness without raising intensity (similarity 0.92)
• Total loudness is the integral of specific loudness over critical-band rate (similarity 0.91)
• Loudness rises once noise bandwidth exceeds the critical band at constant SPL. (similarity 0.91)
• Loudness depends on more than physical sound intensity alone (similarity 0.91)
• Wideband sounds are louder than narrowband sounds at equal dB SPL (similarity 0.90)
• Loudness grows with bandwidth via area tradeoff except at extreme levels (similarity 0.90)
• Loudness stays constant below critical bandwidth then grows beyond it (similarity 0.90)
• The ear sums all sound energy within a critical band into one perceived item (similarity 0.89)
• Loudness rises with bandwidth beyond the critical band despite falling pattern height (similarity 0.88)
• Loudness depends on frequency, angle, duration, and envelope, not just level (similarity 0.87)
• A sound’s bandwidth independently affects how loud it sounds. (similarity 0.87)
• A-weighted sound pressure level misrepresents the loudness of broadband noises (similarity 0.86)
• Loudness perception requires a tenfold intensity increase to double (similarity 0.86)

Broader Connections

• Loudness grows when sound energy spills beyond a single critical band #expands (0.92)
• Spreading a sound’s energy across more critical bands increases perceived loudness without raising intensity #expands (0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 665
• Wider bandwidth increases perceived loudness at equal sound pressure #expands (0.85) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 868
• Loudness depends on more than physical sound intensity alone #corroborates (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 2610
• Loudness grows with bandwidth via area tradeoff except at extreme levels #expands (0.80) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1288
• Loudness depends on frequency, angle, duration, and envelope, not just level #corroborates (0.72) — Toole, Floyd E, Sound reproduction- the acoustics and…, 903