IN Get Smart, the 1960s TV spy comedy, secret agents wanting a private conversation would deploy the , a clear plastic contraption lowered over the agentsâ heads. It never worked â they couldnât hear each other, while eavesdroppers could pick up every word. Now a that we are assured will work is being patented by engineers Joe Paradiso and Yasuhiro Ono of the Massachusetts Institute of Technology.
Their idea, revealed in on 16 April, is to make confidential conversations possible in open-plan offices and canteens. It will even let a conversing group move around a room and still remain in a secure sound bubble.
âIn increasingly common open-plan offices, the violation of employeesâ privacy can often become an issue, as third parties overhear their conversations intentionally or unintentionally,â the inventors say in their patent. Their aim is to relieve people of that concern.
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âIn open-plan offices, the violation of employeesâ privacy can often become an issueâ
Instead of plastic domes, they use a sensor network to work out where potential eavesdroppers are, and speakers to generate a subtle masking sound at just the right level.
It sounds simple, but it needs quite a bit of infrastructure. The walls of the room must be peppered with light-switch-sized units that include a microphone, a speaker, an infrared location sensor and networking circuitry connected to a server. When somebody wants to activate what the MIT researchers call the âsound shieldâ, they do so on their desktop computer. Knowing the position of the computer, the sensors identify the person and map out the locations of people around them. Software assesses who is so close that they must be participants in the conversation, and who might be a potential eavesdropper.
The array of speakers then aims a mix of white noise and randomised office hubbub at the eavesdroppers. The subtle, confusing sound makes the conversation unintelligible.
The ideas are not completely new â but what has gone before has big limitations, says Paradiso. âCurrent systems put sound out from one source. The sound isnât generally placed optimally between potential listeners and the people in conversation so there can often be too much or too little masking noise.â
For instance, the , from Sonare Technologies, is a radio-sized machine with two speakers that emits white noise from your desk to mask what you are saying on the phone. But it is over-noisy, say the MIT team, and also fixed in place, whereas their systemâs sensors can track people as they move around, and shift the masking noise accordingly.
If they decide to press ahead and exploit the idea, the system will also advise users whether there are other people too close by for it to assure secrecy. âWith people often working in large open-plan spaces now, the time has come for ideas like this,â says Paradiso.
Klaus Moeller, founder of sound-masking systems maker Logison of Oakville, Ontario, Canada, is impressed with MITâs ambition but doubts its practicality. Logison uses a proprietary technology called Accumask that masks only speech frequencies to deaden voice transmission in offices â and it needs few fittings.
âI wish MIT the best of luck with their idea,â says Moeller. âIt sounds very expensive and not very practical in an office environment.â He thinks architects may object to the many wall or ceiling-mounted devices the system needs to follow people around the office.
