Putting a notch into digital sound.Putting a notch into digital sound
Digital audio tape See DAT.
(storage, music) Digital Audio Tape - (DAT) A format for storing music on magnetic tape, developed in the mid-1980s by Sony and Philips. As digital music was popularized by compact discs, the need for a digital recording format for the consumer existed. offers the possibility of making crystal-clear copies of recordings, with none of the background hiss typically heard on tape. However, that possibility alarms the recording industry, which has been championing an electronic system designed to prevent people from freely copying recorded music recorded music n → música grabada . After five months of tests done at the request of three congressional subcommittees trying to resolve conflicting claims, the National Bureau of Standards National Bureau of Standards: see National Institute of Standards and Technology.
National Bureau of Standards - National Institute of Standards and Technology (NBS (National Bureau of Standards) See NIST.
NBS - National Bureau of Standards: part of the US Department of Commerce, now NIST. ) in Gaithersburg, MD., last week concluded that the proposed copy-prevention scheme "does not achieve its stated purpose." Moreover, some listeners can hear a difference in sound quality.
The copy-prevention system, developed by CBS Records
NBS researchers found that such a copy-prevention system is not foolproof. Sometimes the system allows notched music to be recorded, and sometimes it fails to record music that is not notched. Moreover, NBS engineers designed and constructed five different circuits that could be attached to a tape recorded to defeat the copy-prevention system. According to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. NBS, a competent electronics technician could build any of these circuits for about $100 in parts.
Because the system requires the deletion of certain frequencies from a recording, another key question was whether a listener can readily hear the difference. A series of listening tests showed that for some listeners and for some musical selections the inclusion of the notch has a discernible effect.
The effects of the notch are "extremely subtle," says Irwin Pollack of the University of Michigan (body, education) University of Michigan - A large cosmopolitan university in the Midwest USA. Over 50000 students are enrolled at the University of Michigan's three campuses. The students come from 50 states and over 100 foreign countries. in Ann Arbor, who conducted the listening tests. "I reject the extreme position that the [system's] action is so evident and pervasive that it will be immediately recognized by unsophisticated listeners. I also reject the extreme position that the [system's] action is so benevolent that it cannot be detected." However, there is enough of a difference to warrant caution about allowing such electronic tampering.
"The record industry and the electronics industry have strived for the last 20 or 30 years to get towards perfect reproduction of sound," says Gary Shapiro of the Home Recording Rights Coalition in Washington, D.C. The proposed copy-prevention system represents a step backward, he says.
The Recording Industry Association of America, also based in Washington, D.C., says it accepts the NBS results. But the association plans to continue pressing Congress for some form of copy-protection or compensation.