This August is a month of anniversaries – the 100th year since the opening barrage was fired at Passchendaele, and 70 years since Indian independence and the terrible trauma of partition. And the narrative of each historic event has been illustrated by the voices of people, mostly long dead, who lived through it. The magical power, the tingle, of hearing the authentic voice, catching each pause, the particular pitch of bravado and the tone of remembered horror: this is not the history of document and textbook, it is not the word of money or power; it is what happened to working men and women.

Oral history, the collection of the reminiscences of ordinary people as a valued part of the story of a time or an event told from the perspective of those who were caught up in it rather than from the view of the elite that orchestrated it, is younger than either of the two anniversaries commemorated this month. It has developed only since the 1950s, dependent on portable recording equipment and an appetite for a new, democratic history pioneered by Charles Parker’s radio ballads. He, with the folk musicians and activists Ewan MacColl and Peggy Seeger, recorded the working lives of fishermen and steelworkers, railmen and miners, and the women who worked alongside them. They produced a series of radio documentaries quite unlike anything the BBC had ever produced before: a mix of voice and song with nothing else to break the spell of time and place.

A parallel development was being pioneered by the historian and socialist Paul Thompson, who became part of a wider New Left historiography that sought out the lives of ordinary people to tell the story of history from below, a way of uncovering a radical message about power and agency. That in turn generated a debate about the relative roles of the subject and the interviewer, the nature of the narratives that people construct for themselves, and the authority of those who hear them to interpret them differently. Oral history crosses the boundaries of both archive and voice to become something new again: a cultural instrument.

That is most true in the work of the Nobel laureate Svetlana Alexievich, whose first book, about the women who fought in the Soviet army in the second world war, has just been republished in a new English translation. The Unwomanly Face of War, first published in Russian in 1985, is composed of interviews conducted in the 1970s, when the legend of the Great Patriotic War was still – as it has become again under Vladimir Putin – a central element of national identity.

The veterans that Ms Alexievich interviewed had never thought of themselves as individuals, young women whose lives had been brutally transformed by life on the frontline. Instead their experience of the war was either obliterated entirely, or inserted into someone else’s narrative. In the process of restoring to them their own memories – the injunction to look pretty, or the sound of tanks driving over bodies, or the experience of killing – Ms Alexievich orchestrates an account of what it means to be human that, despite being words on a page, sounds in the reader’s head like a requiem.

Svetlana Alexievich rightly says she is a writer, not a historian. In her hands, the spoken word, even written down, conveys the vividness of individual experience, for it has the power of witness.