Audyssey Updates Dynamic Volume For TVs

Publish date:
Updated on

Los Angeles -

Audyssey Laboratories

is updating its

Dynamic Volume

technology, currently available in select AV receivers and TV sets, with a TV-dedicated version optimized for two-channel playback and small TV speakers, said Audyssey co-founder and CTO Chris Kyriakakis.

Like the current version of Dynamic Volume, the new version - called Audyssey Dynamic Volume TV -- tackles volume-fluctuation issues not covered by the

Commercial Advertisement Loudness Mitigation (CALM) Act

, which mandates that broadcasters and cable operators set a uniform loudness level for commercials and TV programs. CALM, which goes into effect early next year, also imposes mandatory broadcast standards designed to deliver uniform channel-to-channel loudness levels.

The two issues not addressed by the CALM Act but tackled by both versions of Audyssey Dynamic Volume technology include volume fluctuations that occur when a TV's video inputs are switched among different video sources. The second issue is volume fluctuations occurring when a TV program transitions from soft to loud scenes, often blowing listeners out of their chairs when a program transitions from a dialog scene to an action scene.

The latter issue is a byproduct of soundtracks being mixed in ideal listening conditions, Kyriakakis explained.  As a result, soundtracks contain wider dynamic range than can possibly be experienced comfortably at home. "A home's background noise buries the soft passages, and when you turn up the volume to compensate, the loud passages are too loud," he said.

For use in TVs, the new TV-dedicated version of Dynamic Volume uses a revised algorithm that deletes the volume solutions addressed by the CALM Act, enabling the technology to focus more on resolving a TV's remaining volume-fluctuation problems and take into account the small low-power speakers in a TV, the company explained.

 The new technology, for example, expands "the library of reaction times to cover more detailed changes in movie and TV content," a spokesman said. By using a library of reaction times, he explained, Audyssey Dynamic Volume TV avoids the "pumping" sound created by competing technologies that use Automatic Gain Control (AGC). AGC "suffers when content changes from soft to loud and back to soft continuously as in movies," the spokesman said.  "AGC methods tend to overshoot and then backtrack, and this causes pumping artifacts." Dynamic Volume, in contrast, "uses a look-ahead buffer to estimate the rate of change in content level and then adjusts the timing of the reaction [based on a library of reaction times] to avoid AGC-type artifacts."  

The revised technology also compensates for small low-power speakers, which cannot play loud without distorting, by perceptually matching the content's dynamic range [soft to loud range] to the TV speakers' available dynamic range, the company said. Typically, a spokesman explained, soft portions of content are inaudible through TV speakers because of background noise in the room, and the loud parts are "lost" because the system can't reproduce them, the company continued.

Like the current Dynamic Volume technology, Dynamic Volume TV also dynamically and automatically compensates for the human ear's lower sensitivity to bass and treble sounds as volume levels decrease.

Dynamic Volume TV will probably be available in TVs in the first quarter of 2012 in the U.S., Audyssey said. Settop boxes with the technology could be available as early as the fourth quarter of this year.

Technologies from companies such as SRS Labs and Dolby Labs also address all of the volume-fluctuation issues of the Audyssey technologies. SRS Labs's TruVolume, for example, is available in most Vizio TV sets and in Vizio soundbars and in almost all Samsung TVs in the U.S., a spokesman said.

Dolby Volume is in select Toshiba TVs, Dolby said.


Related Articles