Despite the NYPD's assurances that they won't use the tool to hurt protesters, Bill Dobbs of United for Peace and Justice, which has planned protests around the convention, has told reporters that the sound system presents "a potential Big Brother nightmare."
Inside the convention center, people will have the chance to experience — at will — another of Norris's inventions.
A TIME magazine display at the convention will feature speeches of past Republican presidents in tightly controlled beams of HyperSonic Sound (HSS). Viewers can literally step in and out of the display's different listening zones. A similar high-tech display of former Democratic presidents was featured at the Democratic National Convention in Boston in July.
HSS works by mixing regular, audible sound with two beams of super high frequency, inaudible sound waves. "Just the way artists mix their paint," says Norris.
The resulting ultrasonic sound wave can then be directed out in a tightly controlled beam. Wherever the beam makes contact with air, the air molecules interact in a way that isolates the original audible sound. So if you're standing in front of the ultrasonic sound wave, you can hear the sound. If you're a few inches away, you hear nothing.
This cuts down on ambient noise and gives listeners the somewhat eerie effect that the noise is inside their heads.
"We like to say we create silence instead of noise," said Norris. "You don't need to fill the space with a whole cacophony of noise."
The GOP convention display should perk up the ears of some curious attendees, but Norris is most excited about the device's marketing potential.
Already, some Coca-Cola machines in Japan are equipped with the technology so passers-by hear the enticing sound of soda being poured into a glass of ice. And dozens of Safeway supermarkets in California, Colorado and Virginia are testing the technology on patrons waiting in line to pay. Norris' company has also sent out HSS for testing at Wal-Mart and McDonald's. The narrow beams of sound advertise sale items at the store or restaurant and feature promotional material.
Glen Boire argues the concept is annoying and invasive, but Norris counters, "If you don't want to hear it, you can move your head a half foot away and it will go away."
Needless to say, it won't be as simple for convention-goers and protesters — who may wish to tune each other out next week.