“They fly to Port Moresby in Papua New Guinea and there they take a bus for three days and then they hike over a mountain and then they take a canoe and then they get to this little bay with 300 people.” It’s the stuff of Indiana Jones – but rather than seeking out a treasure hidden in the jungle, the aim of this journey is to collect voices. And the people venturing into some of the world’s most remote places aren’t hardened adventurers carrying whips. Instead, they are “PhD students of 25 with a digital camera, a digital audio recorder and solar panels”, according to Mandana Seyfeddinipur, head of the Endangered Languages Archive at London’s SOAS.

But what the roving linguists find is arguably up there with a lost Incan temple. “They live with the communities for months at a time, and develop social relationships, and talk to them and record them, and then they come back and they give me this SD card,” Seyfeddinipur tells BBC Culture. “I’m such a wimp, I get so teary when I first hold it, because possibly the only record that we have of this language is in this tiny SD card.”