Loudness

A subjective term for the sensation of the magnitude of sound. Generally a 10dB increase in sound pressure level is perceived as a doubling of subjective loudness. At low frequencies (20Hz to 200Hz) an increase of as little as 5-6 dB is perceived as a two-fold increase in the subjective loudness.

See also: Phon, Sound Pressure Level, Zwicker Loudness.