Apple Inc. is developing over-ear wireless headphones with parts that can be swapped in and out, seeking to augment its AirPods business with a high-end audio product, according to people familiar with the matter.

The Cupertino, California-based tech giant is working on at least two variations, including a premium version with leather-like fabrics and a fitness-focused model that uses lighter, breathable materials with small perforations, the people said.

Prototypes of the headphones have a retro look with oval-shaped ear cups that swivel and a headband connected by thin, metal arms. The arms stem from the top of the ear cups rather than the sides, the people added. They asked not to be identified discussing products that haven’t been announced.

The ear pads and headband padding attach to the frame of the headphones magnetically so they can be replaced by the user. That approach is similar to some headphones from Master & Dynamic and Bowers & Wilkins, though those models only have magnetic ear pads. Apple’s more modular design will allow users to customize their headphones like they do with the Apple Watch. The design may also mean the same set of headphones would be convertible from comfort to fitness use and back again, the people said.

An Apple spokeswoman declined to comment.

Apple plans to use similar wireless-pairing and noise-cancellation tech in its upcoming headphones to what is already in the AirPods Pro. The new headphones will use Siri for voice control and have a limited set of integrated touch controls. The product will compete with high-end offerings from Bose Corp., Sennheiser Electronic and Sony Corp., which currently retail around US$350.

The Apple headphones have been in development since at least 2018 and their launch has been postponed at least twice, people familiar with their progress said. The company aims to unveil the product later this year, however complications during final development or from the Covid-19 pandemic could affect the timing and features again, they added.

China’s Goertek Inc. is among the partners Apple has discussed for handling assembly of its headphones, according to other people familiar with the California company’s supply chain, but it’s still not fully recovered from the pandemic’s disruption.

Apple’s ability to do final testing on audio products is also potentially compromised by the company’s virus-curbing measure of moving most of its employees to working remotely.

Apple launched its first AirPods earphones in 2016 when it removed the iPhone’s headphone jack. The product powered the company’s wearables sales, giving it a key growth driver beyond the iPhone. The AirPods were updated with a new version in 2019 and the upgraded AirPods Pro with noise canceling were released in October.

In its last fiscal year, Apple generated US$24.5 billion from accessories, including AirPods, Beats headphones and the Apple Watch, almost as much as it took in from the Mac and about US$3 billion more than the iPad. The accessories business is instrumental to the company’s push to generate more revenue per user as people hold on to their iPhones for longer.

The Apple headphones and AirPods are part of a broader audio product strategy that also includes the HomePod speaker and Beats headphones. Apple is developing a smaller and cheaper HomePod, Bloomberg News has reported. It acquired Beats Electronics in 2014 for US$3 billion and has been updating its hardware range in spite of it competing with Apple-branded accessories.

The new Apple headphones will join a long list of other products in the company’s pipeline, including new iPhones with 5G connectivity, a Tags location accessory, lower-cost iPads and new Macs.