Plenty of people default to wearing a single earbud — keeping one ear free for conversations, podcasts on a commute, or calls at a desk. According to a new Engadget report, that habit comes with a hidden cost: uneven wear and tear that can chip away at the lifespan of the pair.

The mechanics are straightforward. The favored earbud cycles through more battery charges, accumulates more sweat and debris exposure, and takes more physical handling than its idle twin. Lithium batteries degrade with charge cycles, so the heavily used bud ages faster — and since earbuds are sold and function as a matched set, one weak unit drags down the whole product.

The fix is equally simple: alternate which earbud you use for solo listening, and let the case equalize charging between sessions. It's a small habit change, but for earbuds that routinely cost north of $100, evening out the workload is the cheapest longevity upgrade available.