Hacker News Reader

Worth noting that human sound perception is logarithmic, not linear. A 90% reduction in sound is -20dB, which is significant. But in human perception terms, that’s only about a fifth of the range of the typical soundscape which ranges from the 20dB of a quiet room to the 120dB of an ambulance siren.

View on HN

10db actually. 20db would be a linear scaling of 100x.

It depends on the the physical property you're measuring.

For power/intensity ratio, 10dB is 10x; for amplitude ratio, 20dB is 10x.

Loudness is typically measured by "sound pressure level" (dB SPL), which uses the latter (amplitude ratio).

Also, it's worth pointing out that while sound perception (like almost all the perceptions people have, Stevens's power law [1]) is logarithmic, its base isn't exactly 10 or 100. [2] claims that every 20dB (10x) in SPL, the perceived loudness is 4x.

[1] https://en.wikipedia.org/wiki/Stevens%27s_power_law

[2] http://www.sengpielaudio.com/calculator-levelchange.htm

Reply on news.ycombinator.com