MY MOTHER was an avid reader, and she also liked to have someone read aloud to her. On a vacation in Bermuda in 1952, I read her most of the collected stories of Frank O'Conner. We both enjoyed them enormously. She, having been born in Ireland and having spent her girlhood there, could attest to the authenticity of his atmosphere and his dialogue although she was a Clare woman and he a Cork man. In Ireland, a difference of 50 miles can matter a great deal.

Only in reading James Matthews' biography did I discover that my mother and I had become acquainted with O'Connor's work in exactly the right way: by reading aloud. Yeats once told O'Connor: "You must always write poetry as if you were shouting to a man across the street who you were afraid couldn't hear you and trying to make him understand." Yeats in his old age made a point of always including a commonplace word or phrase in his poems to restore "the tone of the human voice speaking."

O'Connor took this advice very much to heart not only in writing his poems but also his short stories. He had a powerful baritone voice and was a superb mimic; he loved to read aloud to live audiences and on the radio. He wrote and rewrote his stories, as many as 50 times, striving always for simplicity and to convey exactly the right tone of his characters. His devotion to the spoken word helped make him one of the great short-story writers in the English language. It also explains the title of James Matthews' biography, Voices.

O'Connor was born Michael O'Donovan, the only child of an orphan servant girl and a hard-drinking, melancholic soldier. He was reared in the slums of Cork, Ireland's second city. Like many lonely, imaginative children, he talked to himself and made up stories to transcend the misery of his reality. All his life, he listened to his own inner voice and the remembered voices of others, his parents, friends, a stranger encountered in a pub, a woman overheard on a train, striving to rework those fragments of speech into revealing stories. He left school at 14 to go to work. Thereafter, he was self-educated and he developed the voracious love of books, the devotion to libraries, and the odd range of information of the self- taught. He learned French, German and, to some extent, Russian; his peasant grandother had earlier taught him Irish. He was at home in the literature of all four languages as well as English. It was an extraordinary achievement but in his mind, it never made up for the lack of university training and degrees. He always remained defensive and underconfident. An honorary doctorate of literature from Trinity College, Dublin, in his last years came too late to relieve those feelings.

While still in his teens, O'Connor and his Cork contemporary, Sean O'Faolain, joined the original Irish Republican Army, saw brief duty in the Irish civil war of 1922-23, and were interned for some months by the government of the Irish Free State. Out of those experiences came O'Connor's first volume of stories, Guests of the Nation, published in 1931. In the title story, the hero and other Irish rebels get to know two English hostages through conversations and arguments with them and through playing cards. Then politics intervenes. The hero obeys an order to kill the two hostages in retaliation for some British government action. Subsequently, the hero is desolate: "It is so strange what you feel at such moments, and not to be written afterwards," he muses. "I was somehow very small and very lonely. And anything that ever happened to me after I never felt the same about again."

This much admired and much imitated (by Brendan Behan and others) story made O'Connor famous in Ireland. Matthews writes: "O'Connor had not indicted the rebels or their cause; neither has he vindicated violence. Rather he has isolated its horrible effects at the moment of impact . . . Guests of the Nation contains those Estranged from his natural father, O'Connor drew emotional sustenance from a series of surrogate literary fathers: Daniel Corkery, AE (George Russell), Yeats. Aided by their patronage and counsel, he learned to manage if not master his volcanic energies, wayward intellectual interests, and uncertain temper. He became a great man of letters and produced works of lasting value in several different fields including An Only Child and My Father's Son (autobiography), Kings, Lords and Commons and Little Monasteries (translations into English of poems in the Irish language), Irish Miles (travel), The Big Fellow (a biography of Michael Collins), and Mirror in the Roadway and The Lonely Voice (literary criticism). He also wrote novels and co-authored several plays that were produced at the Abbey Theatre.

But it is the dozens of short stories that he produced in sudden bursts of creative energy (when as he liked to say he felt he was writing so well he felt sorry for Shakespeare) and then patiently, painstakingly rewrote and rewrote that created his lasting reputation. Many of these stories will be read as long as the English language endures.

In the best Irish tradition, O'Connor was a great talker and a great hater as well as a great writer. Feuds and broken friendships littered his life. The father of five children by three wives, he was an unfaithful husband, an erratic and bad-tempered father, a difficult friend. He was capable of irresistible charm, comic brilliance and intellectual generosity. But he lived by the savage rule that an artist has to put his writing first, ahead of everything else including his family and friends. Selfishness cannot help but be unattractive.

I suspect it is always dangerous to read the life of an author one has admired. Recent biographies of Robert Frost and Thomas Hardy pose that risk, and so does this book. Some readers may come away disapproving of O'Connor's childishly egocentric and irresponsible behavior so much that their reaction interferes with the pleasure of rereading his stories.

But most readers will probably not have that disturbing reaction. Matthews writes extremely well. His book is thoroughly researched, always fair and judicious in its judgments, and candid yet sympathetic. The book is informative and at times entertaining not only about O'Connor and his contemporaries but also about Irish book censorship (now happily abandoned), the Abbey Theatre, and the tone of Irish life from the 1920s to the 1960s.

O'Connor was a provincial. He rarely wrote on any but Irish themes and he returned obsessively to the hidden dramas and unexpected epiphanies in the outwardly drab lives of ordinary persons, many of whom he had known in the Cork of his youth. His own favorite among all his stories was "The Luceys." The problem in writing that story, he once observed, was that despite the constricted quality of small-town life, Irish people were often quite remarkable. "The difficulty in this story was to keep the issues small but the men big."

O'Connor succeeded in achieving that aim. So has his biographer. The contentious issues that embroiled him in life are not discounted, but Frank O'Connor emerges a master storyteller, despite his failings, and a big man.