For example, obj.mfcc = true, adds mfcc to the list of enabled features. Call extract to extract the features from the audio signal. Normalize the features by their mean and standard deviation. features = extract (aFE,audioIn); features = (features - mean (features,1))./std (features, ,1); Plot the normalized features over time. Digital streaming has become the most popular way to experience music today. Loudness normalization applied by streaming services allows for the restoration of dynamic contrast, yet the hypercompressed production trends sustain. This paper studies current dynamic and spectral tendencies through integrated loudness and long-term average spectrum (LTAS) analyses of popular music playlists.