Dialogue Normalization – Benefit or Menace?
So let’s say we pick a single movie with its soundtrack available at the same bit depth resolution in both uncompressed and lossless formats, like the ‘Troy: Director’s Cut’. Now we should finally have a case where playing the Blu-ray’s PCM track and the HD DVD’s TrueHD track back-to-back should sound instantly identical, right? Well, almost. Now there’s a new wrinkle to consider. Many Dolby audio tracks are encoded with a function called Dialnorm, which is short for Dialogue Normalization, a feature Dolby offers to set the default playback levels. The idea is to avoid having some discs start very loudly and others start very quietly when a receiver is set for the exact same volume. To do this, Dialnorm sets a default center of the soundtrack at a common average, using dialogue as a baseline. Therefore, the relative loudness of movie dialogue should be the same from one Dialnorm-encoded disc to another without a viewer needing to change the receiver volume from normal preferences. Ther
