A patent application published by the U.S. Patent and Trademark Office on Thursday reveals Apple is investigating a unique set of headphones, designed to withstand the rigors of athletic activity by eliminating the need for cumbersome cords.





The invention, titled "Detachable wireless listening device," describes headphones designed to free listeners from the burden of wires by leveraging wireless transmission technology, such as Bluetooth.

Apple notes that, while inexpensive and efficient, common wired headsets like earbuds are "susceptible to becoming entangled while the end user is participating in physical activity." The situation can be "particularly nettlesome" since the cord is somewhat firmly affixed to the portable media player by a 3.5mm plug, which can be a potential hazard to both the device and its user.

To solve the ever-present trouble of wired connections, Apple suggests a type of hybrid system that can receive audio data through a cable as with traditional earbuds, but can also be detached from the device and operate wirelessly when needed.

The clever "listening device" is connected to the player by either a physical clip or detent, or a series of magnets. When attached, the headphones are able to use the cord as an RF antenna with data being processed by the host device, and a means of power for charging a set of built-in batteries. While connected, the headphones receive audio signals through the cable and are able to tap into the media player's power supply if needed, thus saving precious energy for untethered use.

If the headphones becomes detached, either by the user or unintentionally, the host device seamlessly pauses the charging process, activates a wireless module and begins to send audio over Bluetooth of some other form of radio communication. The patent notes that stereo audio can be provided to the wireless headset by assigning each side, right and left, a unique wireless address.



Illustration of wireless headphones connected to and charging from media device (left), and detached running in wireless mode (right).

Apple cofounder Steve Jobs famously said in 2005 that Bluetooth was simply not suitable for headphones because the bandwidth was too low for high quality sound reproduction, and people are loathe to charge both an iPod or iPhone as well as a peripheral.

That was arguably true seven years ago, however the advent of low-power Bluetooth 4.0 components, combined with Thursday's unique hybrid headphone invention, could one day lead to the level of technology Jobs was waiting for.



