Calculating And Adjusting The Perceived Loudness And/Or The Perceived Spectral Balance Of An Audio Signal

An apparatus for controlling a perceived loudness of a digital audio signal, comprising:

• a subsystem, implemented at least partially in hardware, that derives scale factors from the digital audio signal to reduce a difference between the perceived loudness and a target loudness, each scale factor respectively operating in a frequency band of a plurality of frequency bands;
• a subsystem, implemented at least partially in hardware, that applies the scale factors to the digital audio signal to reduce the difference between the perceived loudness and the target loudness,
• wherein the perceived loudness varies both with frequency and acoustic level.

A non-transitory computer readable medium, storing software instructions for controlling a perceived loudness of a digital audio signal, which when executed by one or more processors cause performance of the steps of:

• deriving a plurality of scale factors for the digital audio signal, each scale factor respectively operating in a frequency band of a plurality of frequency bands;
• applying the plurality of scale factors to the digital audio signal to reduce a difference between the perceived loudness of the digital audio signal and a target loudness,
• wherein the perceived loudness varies both with frequency and acoustic level.