Jewellery, alcohol and lots and lots of headphones lost by the 40 million passengers who travel through Australia's busiest airport each year are being auctioned off.

The Sydney Airport lost property auction, beginning on Monday, hopes to raise funds to pay for swimming lessons for thousands of local children.

"This auction is more than just a chance to score a great find, it's about giving back to our local community," the airport's corporate affairs general manager Josh Clements said.

More than 2000 items are being auctioned off, with bids starting at $10.

Shortly after the auction started, a pair of Apple AirPods Pro, JetBlack sealed in their box, was leading the interest, with 21 bidders pushing the price up to $200, with more than a week before the auction's end.

Those chasing a bargain may be more interested in other lots listing multiple pairs of the popular headphone, with pictures showing varying degrees of damage, questionable cleanliness, and unverified authenticity.

Residents living near the airport may be interested in several other noise-cancelling headphones on offer.

Laptops and e-readers are some of the other items frequently taken aboard, and subsequently lost by flyers, as well as abandoned airport purchases such as perfumes and duty-free-sized bottles of spirits which make up a significant number of auction items.

The airport curfew reduces noise between 11pm and 6am but those struggling to sleep for other reasons could pick up a cheap CPAP sleep apnoea treatment device, among some of the more unusual finds.

Other oddities include an Electrolux vacuum cleaner, and an unrelated, and perhaps erroneously titled, "Hooverboard" - likely abandoned by a traveller unaware the self-balancing mobility devices had been banned from the air by many carriers.

Popular items on Monday morning included an 18ct gold bracelet, with 19 bidders pushing the price up to $600.

A black Gucci bag had 14 bidders willing to pay up to $320.

The auction is being conducted by Theodore Bruce Auctioneers & Valuers.

Director Casi Prischi said the auction is one of its most loved events.

"People from all over Australia log in to bid, not just for the bargains, but because it supports something meaningful."

The airport has kicked in $100,000 with hopes the auction can secure another $200,000 to fund swimming lessons for children in Sydney's inner west, over where planes descend on approach to the airport.