07072477 is referenced by 113 patents and cites 10 patents.

Automatically normalizing a perceived loudness for a digitally encoded audio track formed of a number of channels during playback on a multimedia asset player is described. A number of auditory selectivity frequency bands are selected and for each channel in the track, a power value for each of the number of selectivity frequency bands is computed. Each of the power values is weighted by a sensitivity weighting factor and a sum value of all the weighted power values is then calculated. For the track, a perceived acoustic power value is calculated based upon the sum value for each of the channels and a normalization gain factor based upon the perceived acoustic power is calculated and associated with the track. During playback, the normalization gain factor is applied to the track.

Method and apparatus for automatically normalizing a perceived volume level in a digitally encoded file
Application Number
Publication Number
7072477 (B1)
Application Date
July 9, 2002
Publication Date
July 4, 2006
William S Kincaid
Palo Alto
Beyer Weaver & Thomas
Apple Computer
G10L 19/00
G10K 1/064
G08B 3/00
H04R 29/00
H03G 3/00
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