NEW YORK (AP) From his nosebleed seats just under the closed, retractable roof at Arthur Ashe Stadium, Dave Harris had to raise his voice to be heard.

It's not exactly what he expected from his first trip to the U.S Open. A constant, low-grade noise between a buzzing hive and a rushing waterfall that some fans suspected was a combination of the collected murmurs of more than 20,000 fans, the rush of cool air from ducts and a rainstorm pounding on the Teflon fabric roof.

''It's too loud,'' grumbled Harris, who traveled from Jackson, California, to bring his grown son to the tournament as a birthday present. ''All the sound just stays in.''

Fan complaints rose above the din on a rainy Thursday that gave them their first extended look at what happens when the world's largest tennis stadium becomes the world's largest tennis arena. While all acknowledged it was better than having to deal with rain, most said it created an atmosphere that will take some getting used to.

''It's like watching tennis in an aircraft hangar,'' said Max Linnington, a British expat who lives in New Jersey.

''It accentuates all the sounds,'' he said. ''I prefer it without the roof, actually.''

Leslie Leith-Tedeschi, a Manhattanite who has been coming to the matches for years, said the buzz is mostly people's conversations. ''They used to just go up in the air,'' she said. ''Now they bounce off the roof.''

The chair umpire made quite a few requests for quiet during a Thursday night match, at one point pleading, ''Ladies and gentlemen, respect the players. Please remain quiet ... Your voices are carrying to the court.''

Italian player Andreas Seppi was more blunt from his experience on the court. ''The people, I think, are used to going to baseball and keep talking.''

Second-seeded Andy Murray noted that the closed Ashe was loud, definitely louder than the retractable-roof stadium at Wimbledon but that it was up to athletes to adjust to such variables. Ultimately, Murray said, it will be up to the fans and the television networks to decide if major changes need to be made.

U.S. Tennis Association executive director Gordon Smith said tournament organizers were collecting data on the $150 million roof but that, so far, he hasn't heard a ''peep'' of complaints from spectators. Regardless, he said, ''we've got a new venue, obviously when you enclose a building you're going to expect some additional noise.''

''It's passionate,'' he said. ''We want our New York fans to be passionate. It's really a positive, great atmosphere in there.''

At least one fan watching Murray's match agreed. Liat Haigh of Australia said more important than any noise issue was the relief that she didn't have to worry that her trip to see the U.S. Open wouldn't be ruined by rain.

''I've come a long way and I want to see the tennis,'' she said, dismissing any buzz about the buzz. ''It's part of seeing it live and part of the atmosphere. If you don't like that, watch it on television.''