The Fuser increases your awareness of the natural sounds around you using its built-in microphone to "mix" the music in your headphones with the outside world, allowing you to enjoy your music while still hearing yourself and others around you talk, laugh, work, play. Increase your awareness of traffic around you while jogging outside, Listen to music at work and still engage with co-workers, Take a road trip and not ignore others in the car, Relax at the beach with your music and still hear the waves crash... The possibilities are endless. *Fuser can also be used without a music device as a powerful hearing aid.Watch it in action here: http://youtu.be/cARfDhxaefk