TECHNOLOGY

Your ear’s unique shape makes finding quality, in-ear headphones — that don’t cost a lot — an exercise in frustration. 3D printing and mass customization could make affordable headphones just for you. At least that’s the hope driving a team-up between 3D printing company Formlabs and headphone maker Sennheiser. Inexpensive, mass-produced headphones and earbuds use one-size-fits-all designs that are more like one-size-fits-none. They never really fit so they fall out easily. They’re uncomfortable when you wear them too long. And they don’t block ambient sounds so you have to crank up the volume. Manufacturers are stuck. No two people’s ear…