Sound Solutions: Advances in Audio Technology Are Taking Distance Learning to a New Level

Article excerpt

AT NEW YORK'S MANHATTAN SCHOOL OF Music, Linda McKnight is preparing to teach,a Friday morning masterclass in double bass. It wont be much different from any other masterclass--there will be performances, demonstrations of technique by both instructor and students, and a healthy question-and-answer session--except for the fact that while McKnight gets ready in her classroom, her students are some 470 miles away at the Cleveland Institute of Music. They will participate via the internet.

The Manhattan School of Music pioneered this kind of interactive distance learning program in 1996, using it for private lessons, masterclasses, educational outreach, composer colloquiums, professional development sessions, and educational exchanges among schools both nationally and internationally. Multiple cameras provide different views and different perspectives crucial to teaching musical technique--such as close-ups of a hand on a keyboard or string.

The idea itself is not new; colleges and universities have experimented with interactive distance learning for years. What has changed in the nine years since the program began is the quality of the sound--full stereo reproductions that impress even the most discerning audiophile. "In terms of audio as it relates to distance learning, this is innovative," says Christianne Otto, director of Recording and Distance Learning at MSM. "What we've done is taken the technology and adapted it for a live music performance application."

Videoconferencing was not designed for music. In fact, for years, it featured little more than a picture with often tinny, telephone-quality sound to facilitate corporate meetings or distance learning classes.

But now, advances in audio "codecs," echo cancellation, and transmission methods have enabled MSM to connect students and musical artists together around the country and around the world. A codec (short for "coder-decoder") is a device that converts analog audio signals into a digital format for transmission, and then converts them back into analog format on the receiving end to play through speakers. Echo cancellation is a process that removes audio echoes that distort sounds.

"The codecs and echo cancellation units have all dramatically improved," Orto says. "It used to be that echo cancelers wouldn't really understand the complexities of musical sound and would create weird howling sounds and strange artifacts of sounds. The echo cancelers are getting smarter and can handle the harmonics and frequencies of musical sound."

"High-quality sound is of paramount concern in musical video conference," says Orto. "It enables us to bridge the gap of distance to have the teacher here and the student in a remote location. It is really wonderful because it's live, interactive videoconferencing in real time."

Different Tracks

Although audio recording and reproduction predates video recording by only about 50 years, the two technologies have advanced at very different rates. "The microphones have long been sophisticated," says Orto, "but now we can use those sophisticated microphones more effectively, because the video conferencing technology has caught up with us to a degree."

"I think we have done a lot to get the other elements of multimedia together--the picture and data transmission and the integration of other multimedia instructional tools," says Russ Colbert, global education market manager for Polycom, a firm that makes rich-media collaborative applications for the web. "But we've done disgustingly little to get the audio right for the room, and that seems crazy, doesn't it? If you don't have quality audio, what good is all that other stuff?."

Combining sound and video to the degree that Manhattan School of Music needs for lifelike music reproduction, or to provide the ultimate real-time distance learning class--still has hurdles to overcome.

For example, says Orto, even though MSM uses a variety of high-quality condenser and ribbon microphones to capture the sound, "we don't really know on the remote side what it sounds like, so we have to rely on the ears of those on the remote location to give us feedback," she says. …