Oscar, the very first thing you want to try is a different device. That will ensure that it is your headphones that are failing. After that, plug the headphones in and try to bend the wire near the connector in a couple of different directions. Should you hear a scratching sound or should the sound return, you will have to replace the plug. If that does not work. you will have to get to the driver (speaker)and check the wiring from the connector to the driver (speaker) to see if there is a break in the wiring. Uncommon for the wiring to fail on both speakers, most likely a bad plug. Not complicated, but can be tedious.