The decibel multiplier calibrates integer changes to the ear’s just-noticeable differences

Evidence

The multiplier of 20 has a twofold purpose. The first is to make the result a number in which an integer change is approximately equal to the smallest change that can be perceived by the human ear. The second is to provide some equivalence to intensity measures of sound level as follows. — David Howard, Jamie Angus, coustics and Psychoacoustics, 184

Categorization

Category: Factual Claims

• XREF: The about-1-dB just-noticeable-perception design of the scale connects to the difference limen research on loudness perception.

Related

• The factor of 20 in SPL makes one decibel equal a just-noticeable loudness step (similarity 0.90)
• The decibel unit is calibrated to the smallest perceivable loudness change (similarity 0.90)
• The just-noticeable difference quantifies the smallest audible change in a sound (similarity 0.85)
• Loudness perception is logarithmic, which is why decibel scales fit hearing so well. (similarity 0.84)
• A 10 dB change roughly doubles or halves perceived loudness for complex sounds (similarity 0.84)
• Humans discriminate level differences of under half a decibel across a 100 dB range (similarity 0.82)
• A 1 dB level change marks a recurring just-noticeable unit in hearing (similarity 0.82)
• Logarithmic hearing means equal decibel steps need larger absolute pressure differences (similarity 0.82)
• Amplitude discrimination depends on relative loudness increment, not absolute change (similarity 0.82)
• Sound intensity level and sound pressure level are roughly equivalent (similarity 0.81)
• Doubling sound intensity raises the decibel level by exactly 3 dB (similarity 0.81)
• Perceived loudness doubles with every 10 dB increase, not every 3 dB of intensity. (similarity 0.81)
• Amount of masking is expressed as a decibel difference, not an absolute SPL level (similarity 0.81)
• Human hearing perceives huge physical sound intensity changes as barely different (similarity 0.81)
• A 10 dB increase always doubles perceived loudness above 40 dB (similarity 0.81)