11/24/98 - CAN YOUR COMPUTER HEAR THAT VOICE IN THE DISTANCE? Microphone
And Headset Developers Vie To Be First With The Best
Nov. 24, 1998 (VOICE TECHNOLOGY & SERVICES NEWS, Vol. 17, No. 24 via COMTEX) --
Speech recognition software may be on its way to commodity status, but developers of
microphones and headsets are racing to create the ultimate, must-have accessory for speech
applications - something that transmits clear, accurate voice signals from a distance.
"As far as technology goes, headsets have been pretty static over the past 20 years," says
Douglas J. Andrea, co-president of Andrea Electronics Corp. [AND], based in Melville, N.Y.
Andrea Electronics designs, develops and manufactures audio equipment for speech-driven
technology.
"The prior art, to use a term from patent law, is a directional microphone or a pressure gradient
technology," he says.
The state of the art is moving in various directions, from variations on the
headset-and-microphone theme to no headset whatsoever.
But just as gravity for years kept man from reaching the moon, the basic laws of sound
transmission are keeping speech technology users tethered to headsets.
The Closer The Better
"The closer the microphone is to the mouth, the less degradation there will be," says Costas
Papadopoulos, vice president of research and development for Rollinsford, N.H.-based VXI
Corp., manufacturer of headsets for voice recognition. "Outside noises don't find their way into
the voice path of the computer."
Every company goes about the task a little differently. "We do acoustic and electronic noise
canceling," Papadopoulos says. "With acoustic, noise canceling happens automatically.
Electronic [noise canceling] is based on having two microphones in front of you and then
measuring the difference, but [the cancellation] doesn't happen at the earliest possible
opportunity."
VXI's Parrott headset systems feature a microphone engineered to maintain consistent output
under any condition.
Noise Cancellation 101
Andrea Electronics is best known for its active noise cancellation. Essentially, what Andrea
does is use two miniature microphones and "sum them" electronically, explains Andrea.
"One listens to your voice, and that also has background noise, and the other microphone
listens mostly to the background noise. When you sum them together, you electronically
subtract the background noise. That is a breakthrough no other company has in active noise
canceling technology," he says.
Well, maybe not no other company. Linthicum, Md.-based NCT Group Inc. [NCTI], formerly
Noise Cancellation Technologies Inc., yesterday filed a complaint in U.S. District Court alleging
Andrea's patents are unenforceable. (See "Patent Dispute")
Happily Hands-Free
In any event, Andrea is mighty proud of his company's Digital Super Directional Array far-field
microphone technology. DSDA technology uses an array of microphones (typically four),
special software and digital signal processing to adaptively control acoustic signals.
If DSDA works in the real world as planned, then Andrea has solved a very complicated
problem and made headset-avoiders happy at the same time.
"Once you have people moving away from a microphone, it becomes what we call a far-field
microphone," Andrea says. "Then you start having to increase the sensitivity of the microphone
and start getting reflections and distortions of the acoustic environment. You never really hear a
good speakerphone, for example, because what the speakerphone is doing is picking up all the
reflections and all the acoustic properties of the room," he says.
The difference with DSDA is it tracks the voice with a beam, creating continuous input for a
clear voice signal. Two big uses for the new technology should be voice control of automobile
PC-based computers and hands-free dictation.
Hope And Hype
The clarity of speech problem is even more complex than it might first seem, and someone has
yet to solve it, says Douglas Berger, CEO of Dallas-based Ultimate Technologies, a research
firm for noise cancellation technology.
Although Ultimate Technologies doesn't have "a product per se; we have a patent portfolio if you
will, and in particular a patent for voice cancellation," adds Bob Gilbert, who's in charge of
patent licensing and marketing for Ultimate.
That's because Berger isn't satisfied with what his firm or any other has come up with so far.
"The further you separate your canceling signal from the originating point source, the more
difficult it is because the sound wave is going up, down, backwards, everywhere," he explains.
"It's so easy to do, to re-create the nuisance signal then turn around and cancel it out, as long
as they're in close proximity and the point source is easily identified.
"We've had some successes but we're not satisfied to the point that we're ready to go to the
media and say, 'Hooray, we've solved it,'" Berger says.
Berger originally hails from the securities industry, "which is why I tend to get revved up when I
hear hype."
Feet On The Ground
All of this explains why Ultimate has set its sights a little lower, on technology that allows
privacy for users of personal communications systems.
"People answer phones in public places, such as buses, trains and planes and you can hear
the conversation," says Gilbert. "Imagine that you see people's mouths moving but don't hear
anything." That's the technology Ultimate has patented and is refining in hopes that a larger
manufacturer will soon want to license it.
In the meantime, Andrea is trumpeting its recent agreement with Santa Clara, Calif.-based Intel
Corp. [INTC] to include its DSDA technology in future generations of Intel processors. The
resulting reduced costs and enhanced performance should bring speech recognition to a much
broader base of end users, says Andrea.
(Douglas Andrea, Andrea Electronics, 800/442-7787, - andreaelectronics.com; Doug
Berger, Bob Gilbert, Ultimate Technologies, 214/343-3311; Joanne Lipper, NCT Group,
410/636-8700, nct-active.com; Costas Papadopoulos, VXI Corp., 800/742- 8588,
vxicorp.com.)
Patent Dispute
Andrea Electronics Corp. [AND] of Melville, N.Y., yesterday (11/23) gave notice that NCT Group
Inc. [NCTI] of Linthicum, Md., had filed a complaint against it in the U.S. District Court for the
Eastern District of New York. NCT Group is requesting that Andrea declare two of its patents,
both relating to active noise reduction technology, invalid and unenforceable.
Although the patents involved both concern technology particularly applicable to aircraft
passenger headphones, Andrea officials maintain the company does not derive any sales or
licensing revenue from headphones for airplane passengers.
The complaint alleges that Andrea has engaged in unfair competition by misrepresenting the
scope of the two patents, tortiously interfering with prospective contracts between NCT and
existing and potential customers, making false and disparaging statements about NCT and its
products and falsely advertising Andrea's active noise reduction products.
The complaint seeks to enjoin Andrea from engaging in the alleged activities and seeks
compensatory damages of $5 million or more, punitive damages of at least $50 million and
plaintiffs' costs and attorney's fees.
Based on a cursory review of the complaint, Andrea executives say the suit is without merit
and that the company will "vigorously defend itself."
"We're not giving any comments on it," says Joanne Lipper, spokesperson for NCT.
Source: VTSN |
