Humans and their constant barrage of noise cause all sorts of problems for wildlife. But new research suggests noise pollution may do more than impact individual animals—it can potentially modify whole ecosystems by messing with how predators interact with their prey.
How did scientists figure this out? By blasting plants and insects with AC/DC, of course.
For Brandon Barton, a community ecologist at Mississippi State University and lead author on the study published Tuesday in the journal Ecology and Evolution, the original inspiration for seeing how ecosystems handle being forced to chronically rock out came from AC/DC directly, specifically the Australian rock band’s 1980 album Back in Black.
“The reality is, it started with me listening to AC/DC in my car,” Barton told Earther. “I love AC/DC, and I’ve listened to that album a million times, but I thought about that last song on the album—‘Rock and Roll Ain’t Noise Pollution’—and for some reason it just clicked: that’s a testable hypothesis.”
So, in the lab, the team made microcosm chambers, outfitted with a plant (soybean), herbivores (aphids), and predators (Asian lady beetles). They subjected these chambers to a solid set of playlists, including AC/DC’s Back in Black album, a mix of country music (including Willie Nelson and Waylon Jennings), an album by the British folk-punk band Warblefly, a mix of rock music (with some Skynyrd and Guns ‘n’ Roses), and finally, a mix of industrial and city noises, like jackhammers and cars. They counted aphids after exposure to see if the beetles were munching down on more or fewer in response.
The beetles apparently thought that country and folk music slaps, because they carried on their merry way unhindered. But rock music and city noise? Not so much. Listening to Back in Black killed the beetles’ appetite, halving the number of aphids eaten in less than a day, leaving more around to eat the plant. After two weeks of AC/DC blaring, there were 40 times more aphids on the plants than silent treatments, and the plants were noticeably reduced in size.
“I was really surprised that other music didn’t also have an effect, that it was only certain sounds,” Mariah Hodge, a coauthor on the research, told Earther.
It’s not clear at this point what qualities of rock music and industrial noise are driving this effect. Saeed Shafiei Sabet, a behavioral biologist at the University of Guilan in Iran who wasn’t involved in this study, notes that it may come down to certain sound properties of the tracks used.
“I’d be really interested to see the spectral pattern, sound pressure level, and the energy distributed among the spectral frequencies,” Sabet told Earther.
Sabet also noted that it’s hard to precisely translate what happens in indoor settings to an outdoor environment, because indoor environments can alter the impact of sound pressure waves and other factors.
Indeed, the findings come with plenty of caveats, this being a single study that looked at how noise impacts a fairly simplistic ecological interaction over short time periods. Much more research is needed to see how these effects play out in complex, real world settings over the long term.
But the study does suggest we should be thinking about noise pollution as a potential ecological problem. While much scientific attention had been given to testing noise pollution’s direct effect on single species, few studies have looked at whether these effects rippled through the ecosystem.
In particular, the results may have implications for agriculture, considering that lady beetles are an incredibly important form of “biocontrol”, used extensively to cull aphids that plague crops across the world. If the noise from heavy farming equipment is reducing the beetles’ efficiency at doing their jobs, that’s not good, says Barton.
“When we think about the effect of sound pollution, we need to be careful to not just think about the one organism that might be affected—every other animal and plant that that organism interacts with can also be affected,” Barton said.