Chapter 7: Better Phones; Quality Sound

Broadcasting & Sound: Worldwide Duets

The growing availability of audio codecs (coder-decoders that transform audio signals into digital pulses, and vice versa) has opened a wave of high-quality sound transmissions through the end-to-end dialed digital connections of ISDN. Today, high-quality 15KHz (kilohertz) monophonic sound can be sent through a single B channel, with 20KHz stereo transmitted through the two bonded B channels of a BRI.

Two recent albums featuring Frank Sinatra are probably the most celebrated uses of ISDN for the transmission of high-quality sound. For both CDs, Sinatra recorded duets with other leading singers from around the world. At the time the recordings were made in Los Angeles, however, many of the collaborating artists were on location in other cities and even other countries.

In both CDs, titled Duets and Duets II, almost half of the more than twenty artists featured with Sinatra literally "phoned in" their performances through ISDN connections. Aretha Franklin, for example, sang in Detroit, Tony Bennett called in from New York, Charles Aznavour from London, and Liza Minelli from a studio in Brazil. The recordings were taped "live" in Hollywood. After the live recording, both the voice and instrumental tracks recorded in Los Angeles were transmitted back to the East Coast for final editing and production at Manhattan's Music Factory.

Sound transmitted through ISDN has "excellent quality," said Phil Ramone, who produced both albums. "When you hear how wonderful it sounds," he said in an interview, "there is no question about its quality."

The Sinatra recording used EdNet, one of the nation's first networks devoted exclusively to sound transmission. EdNet uses private high-speed T1 connections between New York and San Francisco, with other dedicated connections to Los Angeles, Berlin, Paris and Rome. Dialed ISDN connections "open" this network to individual studios.

EdNet and a similar but unaffiliated company, IDB, offer proprietary sound transmission networks that currently transfer works between many of the nation's most notable studios. Locations around the world use dialed ISDN to tap into these high-speed backbone networks. Both EdNet and IDB use proprietary encoded transmission equipment, which makes them effectively closed systems.

"These proprietary networks are only a beginning," says David Immer of Digifon in Fairfield, CT. "Because ISDN makes it possible to establish a direct "virtual network" between any two points, anywhere in the world." Immer is a sound engineer and producer, who also helps production studios, radio stations and others around the nation select and set up ISDN audio systems.

"A host of new equipment is responding to this market," he says, "and prices are rapidly coming down." Immer also distributes a worldwide directory of ISDN-capable studios, with the types of codec capabilities each has.