Dolby develops fix for inconsistent audio levels in home theatres

Las Vegas (NV) - Dolby promises to automatically control the volume of your TV : Most couch potatoes have clutched the remote control to raise the volume on quiet television shows only to be blown out of their sofas with a surprisingly loud commercial. In front of a select group of journalists at the MGM Grand Hotel, Dolby demonstrated ’Dolby Volume’ and proclaimed that people would "never reach for the volume again."

Dolby Volume technology will first be built into flat-panel television sets and will process digital audio signals to dynamically raise and lower levels, the company said. Incoming PCM audio is processed "psycho-acoustically" and PCM audio is exported. According to Dolby engineers, Dolby Volume will work with all audio signals and won’t care about bitrates or sampling rates. In addition, the processing does not impact the audio signal.

The technology was showed off in a listening room in the MGM Hotel Conference Center. Various pre-recorded television clips were played back to simulate the channel changing habits of an average viewer. At first, engineers demonstrated the clips with Dolby Audio turned off. The result was the typical "riding of the volume controls" or constant fiddling of the volume to raise or lower voices or annoying commercials.

With Dolby Volume turned on, engineers replayed the same set of clips. Company officials told us that the volume control aims for a "comfortable volume level" and would only need to be set once. Quiet scenes were adjusted upwards, while loud commercials were muted to an acceptable level. We did not notice a delay in the audio and the sound quality appeared the same as before.

Brett Crockett, an engineer for Dolby, said that Dolby Volume handles up to 30 db of reduction or amplification giving the technology 60 db of total range. According to Dolby, the adjustments are non-linear and are split into 40 sound bands called "critical hearing channels".

The firm intends provide the technology to semiconductor makers this quarter and estimates that television set makers will deliver the first Dolby Volume-embedded sets by next Christmas. No prices were specified, but executives said that the integration would result in an increase of "more than just a few percent."

For computer users, a software plug-in could be possible. Ramzi Haidanus, senior vice president and general manager of Dolby’s Consumer division, said : "There are no obstacles to making a software product."