Audio For DTV: Great Expectations Or Business As Usual?

In addition to the improvements it makes to video, digital television also provides for stereo audio of exceptional quality, with low distortion, surround sound, wide dynamic range, multiple languages, and special aural services. Broadcasters would be remiss not to take advantage of these built-in features instead of maintaining the status quo of heavily compressed, mediocre-quality sound with minimal features.

As with any new service with which consumers must become familiar, changes at both ends of the DTV system must be made if DTV audio features are to be fully exploited. It may seem premature to suggest using new features so early in the development of DTV. But consider what would have happened if, several years back, broadcasters decided to delay the introduction of HDTV. There would be no HD displays today and no inclination to produce HD programs. The same applies to DTV audio. By offering a few samples of the DTV audio features (surround sound, multiple languages, DVS) early in the DTV deployment, we can begin to educate the broadcaster, consumer, and receiver manufacturer about its benefits.

The ATSC AC-3 audio system (Dolby Digital) provides the tools as well as the technology for new audio services to the viewer. All that is lacking is the understanding by the broadcaster of how to use the system, receivers that have the ability to display the features, and the knowledge of the viewer to use it properly. This is a parallel process with each helping the other determine expectations of the system, what the broadcaster can and will offer, the articulation of the services presented, and user-friendliness on the part of the receiver. In other words, the broadcaster tells the viewer and receiver manufacturer what will be offered, the viewer tells the receiver manufacturer to keep it simple, and the manufacturer tells the broadcaster how to insure the integrity of the process by proper coding (metadata) of the transmitted signal. For the latter, I urge all readers to look at some of the documents about DTV audio implementation at the Dolby Labs website at

The broadcaster tells the receiver manufacturer that programming will be offered with stereo, surround sound, second language, DVS, and other special sound services. The manufacturers respond with receivers that accommodate the features. Manufacturers tell the retailers about the features. Retailers advertise and show the consumers the features. Consumers tell broadcasters what features are desired and useful and the manufacturers about user-friendliness.

Can broadcasters trust the viewer to embrace the new features? Many will. With our current system, there are few if any choices available to the viewer and we can expect that some broadcasters and viewers will wish to keep it that way.

On the other hand, if consumers can learn how to operate compact disc (CD) players, digital video disc (DVD) systems with surround sound, MP3 players, satellite, and cable TV set-top boxes, they can learn how to select audio choices on DTV receivers. Of course we will also expect receivers to have default conditions that are similar to those available today (compressed stereo and selectable SAP).

Within the overall educational process is the enlightenment of sales personnel in retail TV receiver stores. Without them demonstrating new features of DTV, consumers will not know or appreciate what is available and sales may be lost. This enlightenment is a function of both broadcaster and manufacturer.

The alternative to the above is "business as usual," meaning we do the same thing as we have done with analog television. DTV ushers in a new era of quality, flexibility, and services to consumers, the ability for producers' creations to be presented in the manner in which they were designed, and consumer enjoyment of broadcasters' programs and commercials. Let's not leave out product promotion, which often leads to the implementation of new broadcast features (advertisers began using stereo and widescreen well before producers of regular programming). Dialogues between broadcasters and consumer receiver manufactures will insure that the expectations of each will be realized. This is the time for broadcasters to experiment with some of the audio features of DTV

while there are few receivers and few viewers to annoy if the experiments fail. Learning now will avoid problems in the future.

Next time we'll discuss more DTV audio implementation issues. Stay tuned.