To watch the Masters on television is to be transported to the natural, exclusive splendor of Augusta National Golf Club. The verdant course pops in HD, and Jim Nantz’s dulcet voice wraps you in a cozy cashmere quarter-zip. Adding to the effect are the sounds of birds singing from their perches just beyond the fairways. Listen closely and you’ll notice that there seem to be a lot of birds at Augusta National—perhaps even a suspicious amount. Could it be that CBS is piping in chirps?

This is not a new conspiracy theory. In 2001, the network copped to using recorded bird sounds at the 2000 PGA Championship while insisting that the birds heard at the Masters “are live and … indigenous to Augusta.” But, given the relentless cacophony at this year’s tournament, could it be possible that something foul is afoot?

To find out, I contacted the Cornell Lab of Ornithology, which forwarded my request to the lab’s director, John Fitzpatrick. I will confess that I didn’t realize that Fitzpatrick would be as good a source as he turned out to be. When we got on the phone, he told me he hasn’t missed a Masters in more than 30 years; our call briefly interrupted the satellite radio coverage of the tournament he’d been listening to in his car.

“I will confess that when I watch golf on TV, I keep a list of the birds that I see and hear,” Fitzpatrick told me. Years ago, he said, he was watching a golf tournament and noticed some peculiar sounds. “The broadcast was I think from Kentucky [note: it was likely the 2000 PGA Championship, which I referred to above] and I was hearing birds … like white-throated sparrow that don’t exist in Kentucky in the summertime. That’s when I had my first a-ha! moment. There’s some cheating going on here.”

Back in 2000, Fitzpatrick guessed that he was hearing sounds that had been recorded during the Buick Open in Michigan earlier in the season. He managed to get in touch with someone at CBS who, he says, confessed to the ornithological shenanigans. He remembers the network official telling him that he was one of many who had called to complain. “It was good for two reasons,” Fitzpatrick says. “One nice thing was that CBS was very receptive to the input. And No. 2 was that a whole lot of other people had caught them on it. There are still a lot of people who care.”

As for this year’s Masters, Fitzpatrick says he doesn’t suspect any geographical chicanery. “All I could hear was a cardinal and I think an Eastern towhee,” he said. “To the species, they are all accurate as the ones calling there at this time of year in central Georgia.” With his car parked, Fitzpatrick pulled out his computer, opened the spreadsheet, and read to me from the list of birds he’s tracked in previous Masters.

The roster from 2016: “tufted titmouse, Carolina chickadee, Carolina wren, Eastern bluebird, Northern mockingbird, Northern cardinal, Eastern towhee.” He added, “That was kind of a thin year,” then went searching for a better sample. “In 2015, I had great blue heron, red-bellied woodpecker, American crow, American robin, brown thrasher, Northern parula, pine warbler, yellow-throated warbler, chipping sparrow, white-throated sparrow.” He paused. “This was a good year.”

“Between those two years,” he says, “that’s a pretty representative list of birds that are singing in the pine woods of central Georgia.”

But while the species are accurate on this year’s broadcast, he does have some doubts as to whether each and every chirp is being broadcast live. “It does sound like I hear the same actual song from some of these birds that have quite variable songs,” he tells me. “I’m quite sure they must record some good birds at some point and then they slip back through and play them again here and there to add color.”

When reached for comment, a CBS spokesperson said that the network does not use a prerecorded soundtrack.

Even it the chirps and songs were canned, Fitzpatrick wouldn’t consider it to be too serious of an infraction. “The noise is definitely birds recorded there right on the grounds,” he said. “Let’s just call it audio enhancement.”