Over the last few weeks I have been eavesdropping on private conversations. I heard a homeless South African tell a charity worker how moved he was to be offered a sandwich and a cup of tea after walking 20 miles through Lincolnshire; and an elderly Hull woman, reminded by her daughter how much of her life she had spent pregnant with her 10 children, concluding that she “must have been bonkers”. The Listening Project has been harvesting these intimate gobbets and broadcasting them before the Radio 4 news.

The launch of the Listening Project by the BBC and the British Library coincides with the return next month of another pioneering work of oral history: 56 Up, the latest in Michael Apted’s now eight-part series stretching over almost half a century, following a group of ordinary Britons from the age of seven into what is now deep middle age.

Both projects reveal how new technologies can add inestimable value to our bank of collective memory. The Listening Project, which allows anyone to upload their own conversations, is aided by smartphones and computers with inbuilt microphones and audio software, and the ease of editing and placing sound archives online. When Granada’s original 1964 documentary Seven Up! was broadcast, it was the recent arrival of the Ampex video recorder, before which all television was broadcast live and vanished into the ether like a dream, which allowed a medium without a memory to become an evocative archive of our changing daily lives. Even the changing technologies themselves seem to speak of time and transience: the juxtaposition of grainy, 405-line black and white footage of the children of 1964 with high-definition colour images of the same people in later life is inescapably affecting.

Of course, these brief entries into other people’s lives are fragmentary and artificial. We might think we know the heartbreaking story of Neil, the cheerful seven-year-old from Liverpool in Apted’s series who descended into depression and homelessness. But we don’t really. Every life is too misshapen and strange to be enclosed within a project that momentarily interrupts it with a ten-minute update at seven year intervals. The same reservations can be made about the Listening Project, in which people know their conversations are being recorded and the material has been chosen, shaped and edited, perhaps especially to work on and move the listener.

But these reservations tend to melt away when you listen to a couple talking straightforwardly about the husband’s early onset Alzheimer’s, or two retired workers recalling their tears at the closing of Huntley and Palmers’ biscuit factory in Reading. The conversations bump into important bits of social history by accident: measured voices describe their encounters with the Normandy beaches or the Kray twins. It is the messy, unscientific, improvised nature of this kind of oral history that can make it so eloquent.

What is striking about both the Listening Project and the Seven Up films is how much the participants want to be seen as the authors of their own lives. Apted, who describes himself as “a pretty neurotic, ambitiously driven, middle-class person from Ilford” has tended to make sense of his participants’ lives in terms of achievement and reward. In 42 Up, he bravely asked one of the participants, Jackie, if she could have done more with her life, and she bristled: “I’ve just started all over again, but with three children. But that’s life.”

And so a project which began as a way of thinking about the determining effects of social class – a hunch that it has mostly and depressingly corroborated – has also become about what the filmmaker Mike Leigh calls “the entirely disorganised and irrational business of living”. The last time we saw them, in 49 Up, Apted’s subject were simply pottering round, worrying about their now teenage children and aging parents, and most had nothing very concrete to show for the last seven years. But that’s life – and every life, even the most comfortable and uneventful, is a uniquely rich, endlessly surprising and quietly heroic thing. The Listening Project conveys the same sense of inclusiveness. The story of a transgender woman or an asylum seeker sits naturally alongside that of an old married couple contemplating the “last chapter” of their lives.

Oral history is flourishing in other ways. Craig Taylor’s Londoners, a book of conversations with lost property clerks, manicurists and currency traders, will tell you more about the multiform life of the capital than a lifetime reading the Evening Standard. The verbatim theatre of Alecky Blythe, Gregory Burke and others is creating absorbing drama out of recorded transcripts. And the organisation that started it all, Mass Observation, is celebrating its 75^th anniversary with a new wave of interest, its archive better mined than ever by writers and historians like David Kynaston, Juliet Gardiner and Simon Garfield. I hope the BBC Listening Project is being safely stored in a format that can be read in another half century – for Apted’s series of films show that ordinary life, when combined with the passing of time, can be as spellbinding as any family saga.