The following is an article written by Christine Waring, taken from AT&T Bell Labs News, August 2, 1993. It was provided by Duane Bowker of AT&T
TrueVoice Team Answers the Call for Improved Sound
Holmdel - Duane Bowker, John Ganley and Jim James knew they had discovered how to make long-distance telephone calls sound better when eight out of 10 colleagues "down the hall" chose service enhanced with AT&T TrueVoiceSM over current long-distance sound.
So began the journey of the recently announced AT&T TrueVoice, a proprietary, three-year effort that originally was known only to a few at Bell Laboratories as "Project X." The innovation, which is a significant enhancement of the AT&T switched public network, will improve the sound quality of calls placed within the Continental United States and Canada.
The Bell labs patented innovation will make long-distance calls sound clearer, closer and more natural by boosting the lower, or bass, end of the calls' sound spectrum while raising their overall sound level by up to four decibels. The audio result is a "fuller, more resonant sound," explains Bowker, a DTMS in the Network Performance Characterization Department, Holmdel.
Miniature Network
When Consumer Communications Services (CCS) and Network Services Division (NSD) asked for a better-sounding telephone call, James, a DMTS who now works in the Market Measurement and Analysis Division, Holmdel, recalls how he, Bowker, and Ganley created a miniature version of the AT&T Network in the Voice Quality Assessment Lab. They simulated end-to-end telephone call connections to study human hearing, call loudness and bandwidth issues.
The enhancement answered pitch attenuation and volume concerns for long-distance calls, according to Bowker. Everyone has all levels of pitch in their voices, but most of the voice's energy is in the lower, or bass frequency. Because of the physical characteristics of the telephone and the network, much of the bass frequency is lost. "But AT&T TrueVoice compensates for the loss by selectively amplifying the low frequency components in a caller's voice," Bowker explains.
AT&T TrueVoice also automatically brings up the volume of the long-distance call to approximate the decibel level that people usually experience during local calls.
Consumer Input
The "fine tuning" of the project's original findings was accomplished with the help of small groups of consumers who Bowker and James brought into the lab to test successive prototypes of the system. "Over the course of AT&T TrueVoice development, we conducted 37 studies with more than 1,600 people, gathering reaction to connections and voice quality, and used that data to build and improve the product," explains Bowker. At the same time, Ganley, AT&T TrueVoice product manager, organized a cross-functional team of several departments to plan, design, develop and test the enhancement. They included Signal Processing Systems Development, Consumer Services Performance and Operations, Consumer Services Network Technology Planning, and the Consumer Laboratory in Murray Hill, which conducted the consumer marketing studies.
Click here to see more on consumer testing
"To an outsider, it may seem that it took a long time to produce AT&T TrueVoice," notes Chuck Gritton, technical manager, Signal Processing Systems Development. "And it did take quite some time, because it was necessary to conduct extensive testing and trials, just to ensure than no component in our network would be adversely affected. The magnitude of the effort cannot be overstated." Gritton and MTS Andy Stenard, Tom Wasilewski and Dario Parola performed key signal processing and software development for the project.
Technology Challenge
Almost everyone associated with the project agrees that implementation was a considerable challenge. Valarie Gilbert, MTS, Consumer Services Network Technology Planning, says that her department worked on Forced Inter-Toll Routing for AT&T TrueVoice, which ensures that intra-switched long-distance calls will receive the benefit of the enhancement. In addition, the department created and implemented the technology behind the enhancement's marketing promotional platform, with help from the Consumer Services Performance and Operations Department. "The promotional platform was a major project in and of itself," says Gilbert. Television commercials and print advertisements offer an 800 telephone number for customers to call and hear the difference between AT&T TrueVoice and non-enhanced long-distance sound quality. Calls are routed to an outside organization in Omaha, Neb., where a series of instructional messages, stores on Conversant Voice Information Systems, are played back to the callers. By pressing "1" or "2" on their keypads, callers actively control switching the AT&T TrueVoice enhancement on or off. This allows the caller to hear a comparison between current long-distance sound quality and service enhanced with AT&T TrueVoice.
The demonstration message as read by Tom Selleck, AT&T's i Plan spokesperson, was recorded at the Voice Interactive Service Performance Lad in Holmdel rather than at a commercial studio.
"We wanted to record his voice speaking through a regular consumer telephone set and over an ordinary telephone circuit to accurately reproduce the access portion of a typical long-distance call," explains Mitch Mayer, MTS, Consumer Services Performance and Operations Department. Selleck's voice was captured by a Conversant System located in the network, stored as a UNIX system file, shipped to the promotional platform in Omaha, and downloaded onto the Conversant Systems running the AT&T TrueVoice promotional application.
"We wanted to control every variable to ensure that sound was exactly what one would hear during a normal telephone call," Mayer continued.
Phased Deployment
Deployment of AT&T TrueVoice in the AT&T Network will begin in September, and will continue, city by city, through the end of 1994. Bowker says it is necessary to complete the installation in phases to maintain the network's high quality and reliability. "AT&T TrueVoice will touch every trunk in the network, and we've got to account for how it will affect all our operating systems," he explains.
A major television and print advertising campaign for AT&T TrueVoice began July 13. Anyone who wishes to hear a demonstration of the enhancement may call the promotional platform at (800) 932-2000. A Spanish language version of the demonstration can be heard at (800) 792-9100.
Unless otherwise noted this page and all its contents and subdocuments are copyright 1994 by Michael E. Gorman