Method and apparatus for automatically normalizing a perceived volume level in a digitally encoded file

An apparatus for automatically normalizing a perceived loudness for a digitally encoded audio track formed of a number of channels during playback on a multimedia asset player, comprising:

• means for selecting a number of auditory selectivity frequency bands;
• means for computing a power value for each of the number of selectivity frequency bands for each channel in the audio track;
• means for weighting each of the power values by a sensitivity weighting factor for each channel in the audio track;
• means for calculating an average sum value of all the weighted power values for each channel in the audio track;
• means for calculating a perceived acoustic power value based upon the average sum value for each of the channels by determining a maximum average sum value for all channels and dividing the maximum average sum for all channels by a power scale factor used to map the perceived acoustic power value to a predefined range for the audio track;
• means for calculating a normalization gain factor based upon the perceived acoustic power for the audio track;
• means for associating the normalization gain factor with the audio track;
• and
• means for applying the normalization gain factor to the track during playback.