IMPORTANT: Not all TVs have the Advanced Auto Volume circuit. To see if your TV has the Advanced Auto Volume circuit, check the specifications.
To get noticed, television advertisers love to make their commercials really loud. This can lead to unpleasant jumps in volume when a television show goes into a commercial break. Other unexpected jumps can happen when you change channels or switch inputs. Sony corrects the problem with Advanced Auto Volume.
Most movies and high-definition programming is recorded using a 5.1-channel sound track. The main sound is typically sent to the center channel by design. This enables dialog from the actors to appear to come from the screen. Even stereo sound tracks tend to place dialog in the middle. Typical auto volume systems cannot tell the difference between the center channel and the ambient or background sounds. These systems are often aggressively turning the volume down if it jumps too high or up if it jumps too low. An example would be a program where a couple is talking in a car. When the husband speaks, the circuit decides this is too loud and lowers the volume. Before the wife can answer, the circuit decides this is too soft and raises the volume. This can result in highly unstable volume, which is distinctly unpleasant to hear.
The Advanced Auto Volume circuit is smarter. The circuit considers only the center channel, it is less often fooled. The Advanced Auto Volume can be bold and make more powerful adjustments when the commercials come on or there are volume changes.
NOTE: The system also works with a wide variety of program material, including two-channel sound. For two-channel material, the system automatically derives the center channel from the stereo pair.