The Sony MDR-DS4000 headphones are a wireless audio system designed to work with a number of home or business device through an infrared connection. The system consists of a base unit that is attached through an optical digital or analog audio cable to an audio device such as a TV or DVD player. One side of the headphones contains a volume control, and the internal power setting is designed to switch on and off as the users dons or takes off the headphones. The audio system works with 5.1 channel digital surround sound and is compatible with Dolby Digital, Dolby Pro Logic II, DTS, and MPEG-s AAC audio formats. Prices for the model start at $299.99.