Looking at old photos, you start to notice that every decade has a few "tells" – particular items, ubiquitous to that era, that reveal when a picture was taken. Jeans, depending on waist, wash, and circumference of the lower leg, are always informative.

Eyeglasses, because they are ruthlessly trendy, also prove useful. Scrunchies. Hypercolour T-shirts. An abundance of rayon. These are all fantastic clues.

But our as yet nameless period of history will be complicated to identify; the fashion trend cycle spins faster than ever and the idea of a uniform aesthetic is virtually moot. Yet there is one accessory that will instantly identify a scene from the post-noughties, and that is the white buds of a set of iPhone headphones.

That just about everyone these days owns a pair of portable headphones has had unexpected consequences. Namely: we have not necessarily used them to listen to music, despite decades of trying to make that activity more accessible. Back in the early '90s, when boom boxes the size of skis were the height of sophistication, it was hard to think of anything more thrilling than a cheery little Sony Walkman. I used mine to listen to tapes of songs hastily recorded off the radio, station promotions and all. Tapes were so gloriously robust. When one finally spluttered its shiny innards everywhere, you simply got out a pencil and re-spooled the thing. Later on, Discmans offered better sound, but always seemed a little fragile, too finicky to be truly portable. After all, when a CD gave up the ghost, there was no performing emergency surgery with office supplies.

Even though listening to music has never been easier or more reliable than it is on a smartphone, other technologies now jostle for use in the same space. Record players and music videos are both back in a big way after being declared dead as recently as a decade ago. And if you've ever spoken to someone with a voice-activated speaker system, you'll know the unnerving zeal they possess for the device.