Apple wants to make it even easier for your various devices to “talk” to each other, as well as accessories such as headsets. The company has been granted a patent (number 9,680,980) for an “electronic device accessory” that would facilitate this.
Per the patent, a microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories.
An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes.
User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.
Of course, Apple files for — and is granted — lots of patents by the U.S. Patent & Trademark Office. Many are for inventions that never see the light of day. However, you never can tell which ones will materialize in a real product.