Loudness compensation

Loudness compensation is a setting found on some hi-fi equipment and equalisers that increases the level of the high and low frequencies. This is intended to be used at low listening levels, to compensate for the fact that as the volume of audio decreases, the ear's lower sensitivity to extreme high and low frequencies may cause these signals to fall below threshold. As a result audio material may seem to become 'thin' sounding at low volumes, losing bass and treble, the 'Loudness compensation' button (often just labelled 'Loudness' or 'Loud') is intended to rectify this situation. See the section on Loudness for a more detailed explanation of the ears' sensitivity to sound as a function of frequency.