Loudness, measured in sones, depends inherently on frequency content

Evidence

Loudness is the most fundamental of auditory sensations. … The unit of loudness is the sone: the ratio scale referenced against the sensation produced by 1 kHz sine tone with a sound pressure level of 40 dB. This parameter is not considered as a robust auditory scale or data representation. Loudness has an inherent dependency on frequency content. — Almo Farina, Soundscape Ecology, 982

Categorization

• DEFINE: Sone, acum, asper, vacil are the reference units the reader’s index framework needs precisely defined.
• XREF: connects to: Psychoacoustics quantifies physical sound signals into perceived auditory attributes — Almo Farina, Soundscape Ecology: Principles,…, 976; A decibel value is meaningless without an attached reference level — Almo Farina, Soundscape Ecology: Principles,…, 1943; Loudness depends on frequency, angle, duration, and envelope, not just level — Toole, Floyd E, Sound reproduction- the acoustics and…, 903 (+4 more)

Broader Connections

• Perceived loudness depends on frequency content and duration, not just sound pressure level #corroborates (0.95) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 858
• Loudness depends on frequency, angle, duration, and envelope, not just level #corroborates (0.92) — 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
• Loudness scales with frequency squared, requiring large amplitude at low frequencies #corroborates (0.80)
• Loudness grows as a power law of physical intensity so relative changes match #complicates (0.75) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1262