last week i flew in an early emirates a380 – with the small screens in the back and twin holes – only mono came out of them.

Then on the next leg i got one of the newer a380s with the much larger better resolution screens which also had twin ports – but gave stereo out of a single socket.

And in very old aircraft with old interiors you might get two different sized sockets, but I can’t remember the last time I saw one of those.

First time I flew transatlantic, sometime in the 90s, the headphones were acoustic rather than electronic. They had two holes in the armrest that connected to “headphones” that were rubber tubes you stuck in your ears.

In economy these days with any airline that has newish cabins they seem to have gone back to one socket for stereo, so no need for silly adaptors, but previously they’ve been two mono sockets that sometimes seem to be able to provide stereo from one, and sometimes you need the silly little adaptors to get stereo. And in very old aircraft with old interiors you might get two different sized sockets, but I can’t remember the last time I saw one of those.

It’s still all over the place – within the last few years I’ve been in a brand new plane that still had double mono sockets.

The adaptors are interesting as well – I once bought an expensive (£10) branded adaptor that didn’t actually work – they’d put stereo plugs on each leg so, at least on the airlines I tried it on, the socket connector didn’t line up with whatever part of the plug they’d wired. Cheap eBay ones have always been fine.

One other thing to watch for – airline headphones must be very low sensitivity. I’ve got an inline volume control I use with my headphones on planes. The airlines override your volume selection for announcements and a comfortable listening volume on my Sennheisers would leave me deafened when the pilot cut in.