Interview: After half a century, Micheál Ó Muircheartaigh is, indisputably, The Voice. Not just of Gaelic games in Ireland, but also of generations of long-past Irish summers, those clammy days spent squashed in back seats, shivering after an Atlantic visit, eating crisps and sandwiches.

Walk any Irish beach on a Sunday afternoon and before long you will hear the familiar lyricism of Ó Muircheartaigh broadcasting across the provinces. Although his claim to "live only in the present" is wholly believable, his masterly live accompaniments to the GAA championship games of July and August are like a throwback to the era when radio was the chief source of information and entertainment and, in a sense, light in this country.

More than one person has admitted to listening to an Ó Muircheartaigh commentary while driving and getting so absorbed he elected to sit on outside the house and let him sing it out rather than move inside to see the game on television.

There are times when to move from the rhapsodies of Ó Muircheartaigh's take on a game - a delicate union between his sharp eye and hypnotic tone and the listener's imagination - to the bright, prosaic reality of television is a disappointment. The richness of his language, the effortless melting into Irish, the clarity with which he presents the players and the dimensions of the pitch make following an Ó Muircheartaigh commentary a pleasure more than an effort. The listener does not even have to concentrate.

For whatever reason, Ó Muircheartaigh has a peculiar kind of genius for describing Gaelic football and hurling matches as they unfold before his eyes. But surely the foundation is that voice, so musical and clear. Surely even the man himself will admit it has been a gift.

"I suppose it could be part of it," he said reluctantly earlier this week. "Michael O'Hehir always had a great voice and maybe you can be lucky that way. And I always liked listening to Peter O'Sullevan. But I was never conscious of having any particular kind of voice; it was just my way of speaking and I used it."

The reason for the focus on the most famous voice in Irish broadcasting - sports or otherwise - is the publication of the memoir Micheál Ó Muircheartaigh: From Dún Sion to Croke Park. After much resistance, the RTÉ man spent last winter writing about his journey from archetypal 1930s Dingle farm boy to the man who has become as much of a GAA broadcasting institution as the god of his youth, O'Hehir.

In his acknowledgements, he writes that when he informed his family of his decision to commit his story to paper, "the idea was greeted with a mixture of incredulity and hilarity". Helen and he raised eight children in the suburbs of Blanchardstown with a deep love of education and Irish culture, and although they could not but have been aware of their father's estimable place in the GAA community, it was never something that was treated with great solemnity. Radio was just something he did.

Ó Muircheartaigh will admit that, at the age of 75 and with 50 years of broadcasts behind him, his presence - his voice - is as much a part of the championship as the teams which compete in it. Quite how it happened is something that has never ceased to mystify him.

"I do think I have always been followed around by a certain kind of luck. Whatever recognition there is of me is a bit flattering really, because it is really, I believe, a tribute to both the GAA and RTÉ."

It is also, however, a tribute to Ó Muircheartaigh's upbringing in Dún Sion.

Regular listeners to his match commentaries are well versed in his fondness for issuing messages or greetings to listeners in Dublin hospitals, in Kerry, in pubs in Singapore or New Zealand or in their homes. Like O'Hehir, who famously imagined himself describing the game to a particular neighbour down in Clare, Ó Muircheartaigh almost unconsciously draws his listeners into his life, casually talking of where he caught Mass that morning, of whom he met, of what time he arrived at the ground. From the beginning, he could make the listener feel as if he or she was alongside him in the broadcast booth, and that has not changed now that he commands a worldwide Internet audience.

Ó Muircheartaigh managed to localise the most global of Irish national events, the All-Ireland finals, and his flair for doing that can be traced to his childhood in Kerry. In this passage he recalls his first bus journey to Coláiste Íosagáin in Tralee.

"For some reason I did not feel lonely. The fact that I had never been on a bus before might explain the type of glee I felt: I suppose I was never afraid of the unknown. At any rate the bus trip was fantastic, though we were disappointed that Bill Dillon, holder of five All-Ireland medals with Kerry, was not on duty as a conductor that day. We sped eastwards through Lispole, where Bill Casey, another 'holder of five', lived, and on to Annascaul, where Tom Crean of Antarctic fame had a pub and the home district of Paddy Kennedy, who, strangely enough, also had five All-Irelands to his credit." Even in print, this is the quintessential Ó Muircheartaigh sentence; half-confessional, half-humorous and bursting with information presented as trivia.

The Kerry of his childhood was a county that seemed busy with people walking, cycling, rowing, dancing and, most of all, talking. Although he was educated in UCD, Ó Muircheartaigh's early break into broadcasting - he took part in a competition for an Irish-language broadcaster in 1949 at the age of 18 - was the beginning of a lifetime of travelling the length and breadth of Ireland. He still loves driving - this week alone, he expected to visit the western seaboard twice - but agrees that whatever the population, the "feel" of the countryside has changed greatly since his childhood.

"They used to say that when people were on traps, the horses would stop automatically when they met to wait for the chat. I suppose the age of the car ended all that fairly quickly. And the roads are much faster now of course. But you can still detect the atmosphere building, I think, driving to Thurles on the day of a Munster hurling final or to Killarney for a big game. The towns are still the same. And I enjoy travelling, especially at night - it is always fine as long as you have a radio."

It has always been Ó Muircheartaigh's habit to arrive at a ground on match day very early. At the last Ryder Cup in the Belfry, at which he was a spectator, he shocked his son Eamonn by setting the alarm clock for 3:30 in the morning.

"Where in the name of God are you going at that time?" Eamonn asked, ashen-faced.

"To the Belfry, the reason we came here," the father returned.

"And we were there at half-past-five and saw the sun rising over the course and walked around and we had a terrific view to see every shot played," he recalled.

At summer grounds when he is commentating, he walks the pitch early, talks to the ground staff and visits the teams when they arrive. His youngest daughter, Doireann, is the latest family member to assist him with statistics, but although Ó Muircheartaigh researches his teams, he relies more on natural memory and does not consider himself a perfectionist.

A few years ago, on a day out at Punchestown, he headed up to the broadcast booth to visit Dessie Scahill. To his surprise, the great racing commentator O'Sullevan was preparing to call the last race of the evening. He was in his 80s then and was well retired from the BBC, and this commentary was not being broadcast on the airwaves but was merely for the enjoyment of those in the crowd.

"He had all these strips of paper with information about each horse and he was pinning them to the table around him, preparing for this race. I asked him why he was doing this and he told me once, when he started out, a gust of wind had scattered his sheets all around him. This way,he could be sure they were secured. And this was a man who commentated on so many great races, still taking such care to get ready for the last race of the night at Punchestown with only a few people left to hear it. And I found that astonishing."

He has always considered racing commentary a fascinating art and one he had too much respect for to try.

"I often think you can tell the difference between a man who has had a flutter and a man who gambles by watching them during a race. The serious gambler always watches the whole field, trying to spot a threat to his horse and studying the others. And maybe it would be useful for any potential horse commentator to also know a thing or two about gambling."

Golf and dog racing are his other great sporting passions. He continued teaching until the early 1980s, when he also used to train the city-based members of the Kerry football teams in the Phoenix Park, admitting he had "no formal experience of training football teams but an idea of what I would like to do".

Commentating on his charges from his perch in Croke Park was never a dilemma; he adhered to his first rule of remaining objective. "But I like to think the Dublin-based Kerry fellas were always that bit fresher," he laughs.

Family and his celebrated love for Irish have constituted the rest of his time. The Ó Muircheartaigh children are by now scattered around the globe, but all made it home for the publication of his memoir this week. For one night only the house was full again. (Incidentally, the purchase of that house reveals a haphazard side to Ó Muircheartaigh's nature: the Kerry football captain of 1970, Donie O'Sullivan, met the commentator by chance and told him he had just bought a house in Blanchardstown. Ó Muircheartaigh liked the sound of it and asked O'Sullivan to make an offer on his behalf. A day later, the Kerry captain confirmed they were near neighbours. "I was unconcerned about not having viewed it or tested it for flaws I would know nothing about anyway. On my visit to Grange that afternoon I won a medal competition and a voucher that got me a kitchen table and six chairs that have survived to this day.")

On Wednesday, Ó Muircheartaigh dropped his son Cormac to Dublin Airport for a return flight to Singapore.

"He was hardly in the country 24 hours and has football training when he gets back."

Several of the Ó Muircheartaigh offspring now tune in on the Internet to hear his broadcasts, like so many of the diaspora. They will not have to wait long. He continues to broadcast because he loves it.

He does not dwell much on previous recordings - "I might listen to a game after six months or so, but rarely" - nor does he concern himself with how long more he will continue to fill the airwaves on Sunday afternoons.

"There is a saying, 'You will be long enough when nobody will ask you.' I suppose that has been my way - as long as I am asked by RTÉ, I will continue and not worry too much after that."