The U.S. Patent & Trademark Office (USPTO) has published Apple's Revolutionary EarPods Patent Application, describing the company's "breakthrough design" with this accessory.

Apple's EarPods hit the market last September, when the company unleashed its latest smartphone, the iPhone 5. The new EarPods are designed to provide a more natural fit, while providing increased durability and the type of acoustic quality usually associated with higher-end earphones.

Consumers typically use headsets with many portable electronic devices such as mobile phones or portable music players. Such headsets can include non-cable components (jack, headphones, and/or microphone), and one or more cables that interconnect them. Meanwhile, other headsets can be completely wireless.

Headphones come in several different form factors, including over-the-ear headphones or in-the-ear earbuds. The latter are also known as non-occluding earbuds, as this type of headphones typically doesn't form an airtight seal with the user's ear. Without such an airtight seal, the earbuds' acoustic performance can be poorer, especially if two or more speakers are in use.

Apple's patent aims to illustrate ways to solve this issue, and ultimately provide top-quality non-occluding earbuds. The new Apple EarPods have been on the market for months, and the Cupertino giant claims that its "breakthrough design" can take things to the next level.

The earbud has a non-occluding housing, and each speaker contained within this housing can have front and back volumes. Apple used a midmold structure, enabling the front volumes to be tuned independently of each other. The midmold containing the speakers is fixed to an inner surface of the housing, and has a special cavity shaped to tune the front volume of one of the speakers. The cavity in one embodiment, for instance, can be a part of the front volume for a woofer.

Apple's patent details a cross-sectional view of an earbud, which includes a midmold, woofer, front volume, back volume, and tweeter. The woofer and the tweeter are mounted to the midmold, which in turn is fixed to an inner surface of housing. The midmold can provide front volume of any preset size, while the front volume is acoustically isolated from the tweeter and the back volume.

Apple's patent application published on Thursday, Jan. 3, lists Mechanical Engineer Jeffrey Hayashida, now a Google employee, Design Engineer Jonathan Aase, and Julian Hoeing of Apple's elite design team as the inventors. The Cupertino giant filed for this patent in Q3 2011.