Loudness is perceptual while intensity is physical and must be distinguished

Evidence

Loudness is ‘that attribute of auditory sensation in terms of which sounds can be ordered on a scale extending from quiet to loud’ (ANSI-S1.1, 2013). Loudness perception is a relatively complex, yet consistent phenomenon. The theory describing loudness perception is one of the central theories of psychoacoustics. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1124

Categorization

• DEFINE: Establishes the ANSI operational definition of loudness as a perceptual scale, distinct from physical SPL.
• corroborated: 2 independent passages support this claim — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1124