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This media player was designed by José Ignacio Martínez for "iPod Shuffle2020".
Working with HyperSoundSystem technology, the iPod Shuffle2020 employs ultrasound waves that travel straight to the inner ear, allowing the listener enjoy music without any earphones. The Shuffle also integrates a microphone that receives the exterior sound/noises and eliminates them with destructive interference. If you wanna hear everything else besides the music, you can set the microphone to partially eliminate the surrounding sound or pause the device.
source : itechfuture