Humans can typically discriminate level differences of 1 to 2 dB

Evidence

To determine just noticable level differences, pairs of 1 kHz tones are presented. The first tone is the anchor sound and has a level of 60 dB. The second tones have levels of 60.2, 60.5, 61, 62 and 65 dB. Each pair is played twice. Normally you should be able to hear level differences of 1 to 2 dB. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3363

Categorization

• DEFINE: Operationally defines just-noticeable level difference via anchor-comparison pairs, anchoring the reader’s model of the JND construct.
• XREF: connects to: Identification might operate at a different level than researchers measured. — John Drury and Rupert Brown and Roberto González and Daniel Miranda, Emergent social identity and observing…, 120