Ars Technica:

Custom fit earphones, where the some or all of the earphone is moulded to fit your ear exactly, have undergone something of a resurgence. Traditionally worn by musicians, new materials and technologies have given custom fit earphones a new lease of life as a viable option for consumers that demand the most comfortable fit possible. Custom fit earphones have historically demanded a visit to an audiologist to create moulds (which is an interesting experience to say the least), but the arrival of 3D scanners, 3D printing, and new materials mean moulds can be made quicker and cheaper, even at home.

The question is, do custom fit earphones offer a tangible advantage over foam tips, which cost a mere £12 for a set of three? And can the cheaper options compete with a traditional audiologist mould?

I’ve had a few sets of custom fit earphones and have loved (and sadly, lost) them.