AES San Francisco's April meeting was held at the Creative Advanced
Technology Center in Scotts Valley, California. The meeting attracted
forty-five audio professionals from the San Francisco Bay Area.

Michael Goodwin, Jean Laroche, and Jean-Marc Jot are researchers at Creative
developing new applications of digital audio processing. The three were
introduced by Mark Dolson, Director of Audio Research at Creative.

Michael Goodwin described the use of digital processing to make changes to
commonly recognized sound qualities such as "punchiness," "crispness," and
"warmth." Processing is done using a series of digital signal modification
modules controlled by an "interpolation engine" which maps high-level user
inputs to low-level processing parameters. Soft-decision transient detection
improves robustness, minimizes artifacts, and leads to sound modifications
that are pleasing to the ears.

Jean Laroche demonstrated the use of frequency-domain processing to produce
high-fidelity modifications of the human voice. Voice characteristics are
mainly determined by frequency peaks in the spectral envelope, known as
formants. Frequency-domain processing enables voice pitch to be modified
independently of formants, at the cost of 30-40 milliseconds of processing
latency. The pitch is determined by cross correlating the magnitude spectrum
with a comb frequency pattern, and the harmonics are then simply cut and
pasted as desired. A male voice can be made to sound female, or an ordinary
voice can sound like a professional announcer.

Jean-Marc Jot talked about "Spatial Audio via Loudspeakers and Headphones."
He described a software application which allows three dimensional audio
rendering and enhances the listening experience by processing surround
sound. Sound can be optimized for various playback configurations, on
loudspeakers, headphones, or a personal computer.

The evening's presentations were followed by a lively question and answer
session. Mark Dolson pointed out that the ultimate test of research at
Creative is whether new developments enhance the quality of Creative
products and provide better sound to the consumer.

by Paul Howard and Tom Merklein