Apple will reportedly release upgraded sets of its AirPods wireless headphones this year.

"People familiar with the matter" told Bloomberg that the Cupertino firm is working on a second-generation pair to incorporate the Apple W2 wireless chip - as found in the Series 3 Apple Watch.

In addition, they claimed that Apple will also release new AirPods with water resistance to capitalise on the rapidly expanding outdoor fitness market. It is unlikely they will be able to be completely submerged in water, but they'll be able to survive splashes of water, rain and sweat.

Those are tipped for next year, however, rather than 2018.

The ones slated for this year will also be able summon Siri through the command "Hey Siri", much like the iPhone, rather than requiring the user to tap one of the earbuds, it is said. They are known as B288 internally.

As revealed previously, Apple is also releasing an upgraded AirPods case this year. It will enable the AirPods inside to be charged wirelessly on a charging mat or Apple's own AirPower device.