Sometimes a great notion

Editor's note: Somewhere in the world today, a new generation of innovators is putting the finishing touches on the next big thing. This periodic column will profile the companies whose ideas could have an important impact on the future of technology.

Secret codes, 128-bit encryption, the Enigma machine, invisible ink, the red and blue cellophane overlay--all were invented as ways to deliver information without anyone else knowing. Since the dawn of civilization, humans have yearned for a way to send hidden messages.

And now Intrasonics, a start-up in Cambridge, England, says it can send these messages over loudspeakers.

The company, which was spun out of intellectual-property consulting firm Generics Group, an incubator of upstarts, has devised a method for sending wireless signals over ordinary audio speakers so that humans can't hear them. With this same technology, radio stations can unobtrusively transmit ads, Web site URLs, or information about music and artists to in-car cell phones. A major worldwide carrier will begin trials in the next six months.

Media companies and toy manufacturers are already looking at embedding signals inside TV audio scripts. The idea is that when a character on a television show says "jump," a preprogrammed toy at home obeys the command; this is the sort of technology that could help make that happen.

Will all this change the way we live, or is it the next Fishin' Magician? That's the fascinating part about start-ups and new ideas as engineers and designers around the world keep searching to come up with something big.

If Intrasonics succeeds, it will be just the latest in a string of concept sells for the Generics Group. Founded in 1986, the company specializes in creating new companies as well as ferreting out valuable intellectual property in the patent portfolios of large firms.

These contracts now form the bulk of the company's activity. Consulting work for Siemens, for instance, led to the formation of Sphere Medical, which will make blood-gas sensors.

"If we had just been an incubation company, we would have failed a long time ago," said Geoff Waite, CEO of the group's U.S. division.

Radio-controlled Barney toys are a hundred times more frightening to me.

The Generics Group created Absolute Sensors, among other start-ups, a touch-screen pen company that was sold to Synaptics, and Zowie, a toy project eventually scooped up by Lego. The company also invested in Cambridge Display Technologies, which makes polymer screens.

How it works
Does the company's technology work on the dog whistle principle, using sound waves that are beyond the threshold of human hearing? No. If it did, you couldn't send the signals over standard audio speakers.

Instead, the technology revolves around what's called psycho-acoustic masking. Humans tend to filter out what they don't want to hear, especially the pop, fizz and hum of white noise. Intrasonics essentially digitizes recorded messages, and then masks them as nuisance noises. The signals are spread over the audible spectrum and then disguised into the soundtrack. During a crescendo, the signals can be louder than quiet moments and still remain undetectable.

A processor in the receiving unit, equipped with specialized software, reassembles the message and delivers it accordingly. Tests reveal that people don't hear the signals.

One thing the company has going for it is cost--use of the technology would be cheap. To broadcast ads this way, advertisers merely have to embed the signals into a soundtrack and then ship the CD to radio broadcasters. Radio stations would not have to get new equipment.

Do you really want the Muzak track at Nordstrom ringing you up with shopping suggestions?

To understand the signals, new software would have to be burned into cell phones, but additional hardware would not be required. By contrast, to receive Bluetooth wireless signals, phones need an additional chip.

The company, though, may face problems in acceptance. "There have been a couple of attempts through the years. Generally, what has done them in is poor acoustic coupling," said Richard Doherty, principal analyst at The Envisioneering Group. "It works well on demos but doesn't pass the real-world test."

The anti-spam backlash could also hurt. Do you really want the Muzak track at Nordstrom ringing you up with shopping suggestions? Could it be used to open security holes? Computing libertarians are probably lining up to protest already.

Still, it's an intriguing concept. And I wouldn't worry about this opening the door to some insidious form of mind control. Radio-controlled Barney toys are a hundred times more frightening.