Apple invention prevents headphone audio dropouts in hybrid wired/wireless designs
An Apple patent application covering a wireless hybrid headphone system was published by the U.S. Patent and Trademark Office on Thursday, suggesting the company is continuing work on a Lightning-equipped audio product some expect will replace wired EarPods if and when iPhone ships without a 3.5mm headphone jack.

Source: USPTO
As published, Apple's patent application for "Audio class-compliant charging accessories for wireless headphones and headsets" details a headphone device and supporting hardware capable of seamlessly switching between wired and wireless listening modes.
Unlike traditional headphones that terminate in a 3.5mm TRRS (tip, ring, ring, sleeve) plug, Apple's invention employs an electrical connector compatible with both digital and analog signals, requirements the proprietary Lightning protocol satisfies. An ideal connector would employ a plurality of contacts to transfer power and audio data -- via differential signaling -- from a host device to the headphone. This arrangement allows for a single cable to both charge and control the device, eliminating the potential for ground loops that compromise audio fidelity.
In addition to wired contacts, Apple's proposed headphone includes an internal battery, processor, memory and antenna and wireless transceiver package for communicating with a user device. An iPhone, for example, is able to charge the headphone while being communicatively coupled to the device.

The key to Apple's invention is its handling of audio transmission signals. In practice, a user device communicates with the headphone both through wired and wireless interfaces, sending a packet of authentication data (including, but not limited to, audio) over for decision logic processing. This data is used by control circuitry to determine that the headphone connected via wired communication module is the same device as the headphone connected over wireless.
When a successful match is found, audio data sent to the headphone device via wired or wireless communications module is collected in a hardware buffer, or onboard memory. The headphone is able to fall back on this buffered audio when a user switches from wired to wireless playback, or vice versa, an action that normally results in audio dropouts as the system re-establishes communications.
As for design, the document keeps things vague, noting all supporting hardware can fit into in-ear, on-ear and over-ear styles.

Whether Apple will incorporate the technology into a next-generation headphone is unclear. Last November rumors surfaced claiming Apple plans to remove iPhone's 3.5mm headphone jack in favor of a wireless or Lightning solution. The company already fields both wireless and Lightning-enabled audio equipment through its Beats by Dre lineup, but has yet to utilize similar technology in an equivalent Apple-branded product.
Apple's hybrid headphone switching patent application was first filed for in October 2014 and credits Zachary C. Rich, Baptiste P. Paquier, Joseph A. Sarlo and Jahan C. Minoo as its inventors.

Source: USPTO
As published, Apple's patent application for "Audio class-compliant charging accessories for wireless headphones and headsets" details a headphone device and supporting hardware capable of seamlessly switching between wired and wireless listening modes.
Unlike traditional headphones that terminate in a 3.5mm TRRS (tip, ring, ring, sleeve) plug, Apple's invention employs an electrical connector compatible with both digital and analog signals, requirements the proprietary Lightning protocol satisfies. An ideal connector would employ a plurality of contacts to transfer power and audio data -- via differential signaling -- from a host device to the headphone. This arrangement allows for a single cable to both charge and control the device, eliminating the potential for ground loops that compromise audio fidelity.
In addition to wired contacts, Apple's proposed headphone includes an internal battery, processor, memory and antenna and wireless transceiver package for communicating with a user device. An iPhone, for example, is able to charge the headphone while being communicatively coupled to the device.

The key to Apple's invention is its handling of audio transmission signals. In practice, a user device communicates with the headphone both through wired and wireless interfaces, sending a packet of authentication data (including, but not limited to, audio) over for decision logic processing. This data is used by control circuitry to determine that the headphone connected via wired communication module is the same device as the headphone connected over wireless.
When a successful match is found, audio data sent to the headphone device via wired or wireless communications module is collected in a hardware buffer, or onboard memory. The headphone is able to fall back on this buffered audio when a user switches from wired to wireless playback, or vice versa, an action that normally results in audio dropouts as the system re-establishes communications.
As for design, the document keeps things vague, noting all supporting hardware can fit into in-ear, on-ear and over-ear styles.

Whether Apple will incorporate the technology into a next-generation headphone is unclear. Last November rumors surfaced claiming Apple plans to remove iPhone's 3.5mm headphone jack in favor of a wireless or Lightning solution. The company already fields both wireless and Lightning-enabled audio equipment through its Beats by Dre lineup, but has yet to utilize similar technology in an equivalent Apple-branded product.
Apple's hybrid headphone switching patent application was first filed for in October 2014 and credits Zachary C. Rich, Baptiste P. Paquier, Joseph A. Sarlo and Jahan C. Minoo as its inventors.
Comments
But I believe the main motivation is to advance the state of the art. That often leaves a contingent unhappy, and leaves behind old hardware that needs to be replaced, and so there will be a period of griping and handwringing, but as shown so often in the past, the world somehow adapts and we're all better for it. And so too is the environment without having to absorb all those built-in optical drives, hard drives, floppy drives, etc, that Apple removed in previous cycles of advancement and therefore don't exist to occupy landfills at the end of their useful life. I say, march forward.
http://appleinsider.com/articles/15/09/22/apple-prepares-for-thinner-smartphones-with-slim-headphone-plug-patent
I don't think anyone noticed when Apple dropped hard drives for SSDs.
Dropping the headphone jack for lightning would leave us with hardly any choices in audio hardware. All pro headphones use the 3.5mm jack. Unless Apple plans on developing pro Beats headphones then it wouldn't be such a big deal.
There's also the possibility of Bluetooth only but again that brings it's own set of problems.