a unit of loudness level of sound (apparent, subjective sound level); defined as loudness of 1000 Hz sound at the sound pressure level of 20 µPa. See also: sone. loudness sound pressure level linguistics : phonetics noun

The unit of loudness level

a measure of loudness

a subjective unit for loudness equal to the sound pressure level in decibels when compared to an equally loud standard note

a unit of volume that roughly corresponds with dB SPL

The unit of subjective sound level. Defined such that the sound level in phones equals the level in SPL for a 1000 Hz tone. Generally used in tests where listeners are asked when a tone at a different frequency sounds as loud as a 1000 Hz tone, to define the subjective frequency response of the ear. See discussion in the text on music and ears.

Loudness contours. A subjective impression of equal loudness by listeners as a function of frequency and sound level (dB). An increase in low frequency sound will be perceived as being much louder than an equivalent high frequency increase.

In acoustics, a unit of subjective loudness level equal to the sound pressure level in dB compared to that of an equally loud standard sound.

A unit of apparent loudness, equal in number to the intensity in decibels of a 1,000 Hz tone judged to be as loud as the sound being measured.