http://www.creativeapplications.net/sound/knote-by-matthieu-minguet-rope-as-sound-and-visual-interface-for-iphone-ecal/

Created by Matthieu Minguet, knot (e) is a custom built device that offers a new way of using objects that we connect to our mobile devices. The prototypes, shown in the form ropes, harness themselves to revisit the new node as input data. As an extension of a conventional listening device, it allows the user to generate visual and sound compositions by the simple action of “bending the cable”.

excerpt from Creative Applications webpage