April 23, 2014
Global Soundscapes – Crowdsourcing The Sounds Of Earth
Brett Smith for redOrbit.com - Your Universe Online
In conjunction with Earth Day celebrations on Tuesday – Bryan Pijanowski, an ecology professor at Purdue University, encouraged smartphone owners around the world to download and use an app he developed to record the sounds around them.
“I’ve been on a campaign to record as many ecosystems as possible,” Pijanowski, an ecologist at Purdue University, told Wired. “But there’s only so many places in the world I can be. I thought about how I could get more recordings into a database, and it occurred to me: We have a couple billion people on this planet with smartphones!”
While Pijanowski’s campaign may seem like a crowdsourcing novelty, the ecologist insists there’s some real scientific value to the project – namely determining the sonic impact humans are having around the world – particularly in sensitive ecosystems.
“We should get a sense of whether and how we’re making this a noisier planet, which I think we’re doing,” Pijanowski said. “And it should increase awareness of sounds. Hopefully it will make people stop and listen.”
“If we make this part of the Earth Day culture, something everyone goes out and does, we can begin to characterize those sounds and compare them from year to year,” he added.
In a video posted by the Purdue professor’s Global Soundscapes project, Pijanowski said the project has already collected over 500,000 sounds – all of which are available on to hear online.
Noise pollution also affects animals living underwater, and a University of California at Santa Cruz study published in February revealed that spotted seals living in the Arctic are also being exposed to more and more shipping noise.
Unprecedented sea ice melt in Arctic waters has allowed for the opening up of new shipping lanes and this increase in activity means more ships are now passing through previously quiet ecosystems.
“These spotted seals actually hear much better in both air and water than was previously thought based on earlier data for harp seals and ringed seals,” said study author Jillian Sills, a graduate student in ocean sciences at UC Santa Cruz.
In the study, which was published in the Journal of Experimental Biology, researchers used an acoustic chamber to measure the spotted seals’ hearing both in and out of water. The team found that seals were able to hear a four-octave range in the air and a seven octave range underwater.
“In their range of most sensitive hearing, they can detect airborne sounds as well as terrestrial carnivores, like cats and dogs,” Sills said.
“Our findings suggest that we can probably apply much of what we know about harbor seals to spotted seals,” Sills said. “For harbor seals, we know a lot more about how different types of sounds interfere with hearing, and how their hearing sensitivity can be reduced after exposure to very loud sounds.”
“We don’t know as much about behavioral effects as we would like to because it’s so difficult to do research in the Arctic,” she added. “At least now we are starting to learn about the hearing sensitivity of these seals, which is a first step toward understanding how they perceive sound in air and water, and how they might be influenced by increasing noise levels.”