A wireless headset includes a first earpiece and a second earpiece, where the first and second earpieces communicate with each other over a wireless link. In some configurations, the first earpiece includes both a primary wireless interface for receiving audio from an audio source and a secondary wireless interface transmitting a portion of the audio to the second earpiece. The earpieces can incorporate Near Field Communication (NFC) technology to provide the wireless link between each other. The wireless headset can be configured to synchronize audio output at the earpieces, and can also include a second-earpiece detection mechanism that permits the first earpiece to be used in either a stand-alone mode, with audio output at only the first earpiece, or full-headset mode, with audio output at both earpieces when the second earpiece is detected within wireless range of the first earpiece.