Intel wants to replace the 3.5mm audio jack in laptops, tablets, and smartphones with a USB Type-C connector:

USB Type-C has a number of chances to become the standard for data and charging connector for smartphones and tablets running either Android or Windows. However, in the long-term future, Intel wants USB-C to be even more universal (and therefore pervasive) than it is going to be, which is why at IDF Shenzhen part of one of the talks evolved around using Type-C for audio.

Audio receptacles on PCs and mobile equipment are virtually the last remaining analog interfaces of modern devices, requiring certain techniques to maintain a high audio quality and remove interference. Intel proposes to replace things like 3.5 mm mini-jack with USB Type-C which will help to add features to headsets and will simplify connections of multi-channel audio equipment to various gadgets. This is not the first time a company has proposed to replace analog audio on PCs and mobile devices, but so far, nobody has succeeded due to the ubiquity of 3.5mm. Since the industry may still not be ready to go all-digital, there seems to be a backup plan.

The USB-C has sideband use pins (SBU1 and SBU2) which can be used for analog audio in audio adapter accessory mode. Use of the sideband pins should not impact data transfers and other vital functionality of USB-C cables, which should make them relatively simple from the engineering point of view. In this case, the USB-C connector will just replace the 3.5 mm mini jack and may even gain some additional features, such as a thermal sensor in an earpiece [that] could measure temperature for fitness tracking.