Pittsburgh ? They are the sounds of summer, their voices narrating the daily procession of a sport whose traditions and habits, much like a cherished heirloom, are handed down from generation to generation of Americans.

The days of famed baseball announcers Harry Caray, Mel Allen, Jack Buck and Bob Prince have segued into those of Skip Caray, Jon Miller, Bob Uecker and Marty Brennaman, but the ritual never changes. Sit on a porch swing or an easy chair, slide into a car seat or a poolside chaise longue, flip on the radio and listen to the pleasantly paced passage of another season.

But it’s unlikely Harold Arlin, the first play-by-play man 84 years ago on Pittsburgh’s KDKA radio, envisioned technology quite like this. Harry Caray might have uttered a “Holy Cow!” had he cradled a wallet-sized XM satellite radio that enables fans to listen to every game, all season, no matter their location.

Driving in the Dakotas? Backpacking in the Smokies? Catching rays on Virginia Beach? It makes no difference — with a $12.95 monthly subscription and an XM radio that costs as little as $39, baseball is always there, always available, always on, with no 50,000-watt radio powerhouse needed for reception.

Holy cow, for sure.

“If we had that kind of technology when I was growing up … I would have been in heaven,” said Pirates announcer Steve Blass, a 1971 World Series star who grew up a huge Indians fan in Canaan, Conn. “I would have been all over it.”

Indeed, displaced fans — those living away from their favorite teams — are all over it, now that they can regularly hear all their team’s games. Major-league baseball has sold full-season Internet radio and TV packages for several years, attracting a combined 850,000 subscribers last season, but a computer and online service are required. And a TV set and cable or satellite connection are needed for the daily package of televised games on MLB Extra Innings.

Not so with XM radios, which easily can be moved from car to house to boat to cottage — even to the ballpark, where fans can listen to one game while watching another.

Thanks to satellite radio, Dordt College history professor Paul Fessler is reunited daily with his beloved New York Mets, though he lives in faraway Sioux Center, Iowa. Jay Gough, a loans operation supervisor in Lexington, Ky., no longer worries if he can pick up that day’s Reds game via WLW in Cincinnati. And David Nelms, a steel detailer in McGee’s Crossroads, N.C, has gone from having no games available on local radio to having every game every day.

“For the displaced fan, this is utopia,” XM spokesman David Butler said.

Jim Petersen, a San Diego art museum administrator, bought an expensive, high-powered AM radio to pull in Dodgers games, but now gets a near-perfect signal on a less-costly XM radio.

“It would be impossible for me to articulate the pure joy and freedom that the combination of baseball and radio can provide … baseball on the radio is the background to my life,” Petersen said in an e-mail interview. “I have little time to spend on the couch watching TV, but radio doesn’t interfere with an active schedule. It has the ability to transform tedious and boring chores into a wonderful escape to the ballpark while hands and body are busy on autopilot.”

XM Satellite Radio’s $650 million, 11-year deal with the major leagues cost nearly three times as much as rival Sirius’ $220 million, seven-year agreement with the NFL, but XM is convinced it has a more valuable and desired product.

That’s because industry analysts view the NFL as an appointment sport that fans clear their calendars to enjoy each Sunday or Monday, mostly on TV. But baseball, because of its leisurely pace and natural breaks in the action, has long been considered the perfect sport for radio — with the added bonus of nearly 10 times as many games each season as football.

“Baseball is one of the only sports where it is better to hear it on radio than see it on TV,” said Carter Webb, a computer programmer in Columbia, S.C. “There is something about hearing the call and developing a mental picture of the situation as it is happening.”

Of XM’s 4 million subscribers, 1.5 million have signed up since XM’s baseball deal was announced in October, equaling Sirius’ total number of subscribers.

“Our subscriber base is surging, by every measure,” said Chance Patterson, XM’s vice president of corporate affairs.

Some XM listeners are players themselves, or players’ families. Phillies outfielder Jason Michaels’ dad, Earl, listens in Tampa, Fla., then calls his son to review the game. Giants pitcher Jason Schmidt likes keeping up with former teammates, such as Phillies pitcher Jon Lieber.

Even to longtime fans, it is a chance to hear never-before-experienced announcers. This is Vin Scully’s 56th season behind a Dodgers mike, but the first in which fans from coast to coast can tune in on a regular basis.

“Other than TV, I’ve never heard Vin Scully do a game,” Nelms said. “What a pleasure to be able to hear him.”

Scully, whose three innings per game are a simulcast of his TV play-by-play call, isn’t the only veteran voice who suddenly has a much wider audience. So do regionally popular announcers such as Minnesota’s Herb Carneal (44 seasons), Kansas City’s Denny Matthews (37 seasons), the Brewers’ Uecker (35 seasons), the Cardinals’ Mike Shannon (34 seasons), the Reds’ Brennaman (32 seasons, or twice as many as son Thom, now with the Diamondbacks) and the Athletics’ Bill King (25 seasons).

Uecker, like Scully, works without a color analyst — and why not? In one recent inning, Uecker detailed that day’s Klement’s Sausage mascot race, chuckled at the “stone-cold hands” of a Cubs fan who mishandled a foul ball and marveled how angry some non-baseball listeners get when afternoon games delay the traffic report.

Such tongue-in-cheek humor can be found frequently while twirling the XM baseball dial.

Different styles are revealed, too. The Cubs’ Ron Santo is an unabashed rooter, sometimes yelling, “Get up!” to a promising fly ball. Marty Brennaman doesn’t hesitate to criticize his employers.

For now, fans such as Nebraska University student and Royals rooter Nate Rohr who wish they could hear their favorite announcers every night must be content with one broadcast per game — almost always that of the home team.

Barring future advances in computer chip-set or compression technology, XM’s only option to accommodate two sets of announcers per game would be to temporarily turn off some of its 135-plus music or talk channels, something it won’t do.

“There may be occasions when the visiting team is heard, but the plan is to stick to the home team,” Patterson said. “If it makes sense to have dual broadcasts, we’ll look at that, but with 30 different teams, that’s probably more bandwidth than makes sense.”

Still, with so many more ears listening than ever before, it’s a far cry from those not-so-long-ago days when the only national radio games were the All-Star game, the playoffs and the World Series.

“This is the most joyous piece of serendipity I’ve had,” Petersen said.