EQUAL LOUNDESS CURVES
- Just Noticeable Difference (JND): The acoustic value
at which 75% of responses judge stimuli to be difference (also
known as a difference limen).
- The perceptual loudness of a sound is specified via its relative
intensity above the threshold. A sound's loudness is often
defined in terms of how intense a reference 1 kHz tone must
be heard to sound as loud.