(Bloomberg) — Dyson’s plans for an air purifier that could double as a pair of headphones have been published by the U.K. patent office, at a time when face masks have become must-have accessories to fight the spread of a deadly virus across Asia.

The product, developed by Dyson engineers, houses a filter within the headphones, with a form of nozzle providing filtered air to the user. The patent notes that “air pollution is an increasing problem and a variety of air pollutants have known or suspected harmful effects on human health.”

“We’re constantly creating disruptive solutions to problems, which means we file a lot of patents,” said a Dyson spokesman in an email. “If and when a product is ready we’ll happily go through it but until then we don’t comment on our patents.”

Here's how Dyson’s patent filing says it'll work: Both earcups contain a motor that's connected to a fan-like propeller measuring 35-40mm. Each spin at about 12,000 rpm to draw about 1.4 liters of air per second into the headphones through a filter that particles — typically dust and bacteria, although not specified in the patent — cannot penetrate. The filtered air then journeys down each side of the mouthpiece, meeting in the middle, where a perforated air vent jets about 2.4 liters per second of clean oxygen toward the wearer's mouth. However, there is no reference to a battery, or any illustration where one might fit.

The potential to market a wearable purifier to consumers in smog-filled Chinese cities could be a major driver for the project. Chinese President Xi Jinping has declared pollution one of the government’s three most pressing problems. Floor-standing air purifiers are big business in Asia, while there are even a few versions available that can be worn around the neck.

Pharmacies across Asia are also currently sold out of masks aimed at preventing viral infection of the new coronavirus, prompting authorities to say more will arrive next week.

Dyson’s new headphones may never come to market. The company files a large number of patents for products that often don’t make it into production. Last year, it ditched a £2 billion ($2.6 billion) plan to build electric cars.

Asia has been instrumental to Dyson’s recent rapid growth: revenue increased 28% to £4.4 billion in 2018, with sales in Asia helping fuel much of the growth. Shanghai was the top-selling city for its purifiers in 2017.