Soon, audio emails and tweets that only you can hear

Messages whizzing directly over your head and tweets flying around you like a flock of birds. Sounds like science fiction? Not quite!

Researchers at the Technical University of Berlin, Germany, have developed an audio-enabled space called 'BoomRoom' where you can sift through your messages using sound.

The 'BoomRoom' consists of a ring of 56 loudspeakers that direct sound to stationary and mobile positions, creating sound that only you can hear.

For instance, emails and tweets could fly around you like a flock of birds, each chirping a subtly different sound that identifies the sender.

More urgent messages whizz could directly over your head and if you touch one, a computer would read it out, 'New Scientist' reported.

An array of 16 gesture-recognising cameras allows you to control what those sounds do. A music track, for instance, could be assigned to an object in the room such as a vase.

To play the track you simply pick up the vessel and "pour out" a track in mid air. Gestures such as moving your hands apart or bringing them together can alter qualities like volume, treble and bass.

"The instruments exist in mid-air so you can do your own sound mixing," said Jorg Muller whose team developed the 'BoomRoom' alongside Sascha Spors of the University of Rostock, Germany.

The 'BoomRoom' works on a technique developed at the Delft University of Technology in the Netherlands called wave field synthesis (WFS).

This constructs a 3D sound field by cancelling and reinforcing sound waves in much the same way as a hologram does with light waves.

The trick is to use an algorithm that controls the speakers precisely and uses constructive and destructive interference of the sound waves to place sounds where they are wanted, moment by moment.

The technology could enable a future smart room for people who are blind or sight-impaired, Muller said.

If a blind person entered a room, the important objects inside could announce their location. Users could also leave messages for one another in mid-air to be read out by a computer.

The system will be presented at the annual computer human interaction conference in Toronto in April.