DTS TruVolume HD
DTS TruVolume HD technology is a real-time loudness leveling technology with support for stereo and 5.1 that measures and regulates perceived loudness differences to create consistent audio output that matches a configurable target loudness level. Eliminate those annoying fluctuations in volume while watching and listening to content. DTS TruVolume HD responds in real time to different sources and types of content to maintain consistent loudness.
DTS (DTS, Inc.). You can learn more about them at their official website for home theatre.
The description used for this sound format was taken directly from DTS’s own site for the most accurate description available.