There are a variety of ways to send targeted audio, which can only be heard when standing in  a specific are.  Generally this is accomplished by broadcasting sounds at a frequency to high to be perceived by humans, until it encounters specific interference which lowers the frequency into an audible range.  This is currently used for targeted advertising, or for driving people nuts if you consider the two separate. 

Today The Register posted a new way to provide targeted audio, which uses light instead of high frequency audio to transmit the signal.  Previously this was used in medical imaging techniques, this particular application is new.  The light interacts with water in the atmosphere to provide audio to a specific location, using what is termed the optoacoustic effect.  The moisture in question is insignificant, the humidity in the air and that produced by exhalation is enough for this to be effective.  Pop by for more information on this; though there is no confirmation that wearing an RGB headset will enhance or interfere with transmission.

"Water is among a class of materials that can emit sound after they absorb light, and according to a paper in Optics Letters, a correctly tuned laser can be modulated to deliver human-audible sounds this way."

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