Science Diary: Acoustics – Sound
Music
Ambiance: Lake Habitat – CD 070606-3_SD23_TK3
“The question we ask is, is sound a valuable attribute of an ecosystem? And really that’s what we’re testing.”
What can we learn from the sounds of the natural world? Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside. Stuart Gage is a professor at Michigan State University, where he heads the Computational Ecology and Visualization Lab. The lab studies how sound of a place can be used to learn about its ecology.
“And so we set up sound recorders in different types of ecosystems, listen to those sounds, analyze those sounds, interpret those sounds. And so, we’re looking at the value of the sounds to see whether or not we can use them as ecosystem health measurements.”
Stuart Gage divides the audio he collects into 3 types of sounds. Biophony, the sounds of living creatures; technophony, the sounds of machinery, or other human-made noises; and geophony, earth sounds like rain, water, or falling rocks.
Well, basically what we did was to take a small sample of soundwe sample generally at about thirty seconds per sampleand divide up the sound into different levels, different frequency bands. And, the reason why we did that was to look at the different amounts of energy of the sound in each one of those different bands. And so we’re able then to build ratios between the amount of biology there is in the sound to the amount of technology, or technophony there is in the sound to come up with indices of ecosystem health. Assuming that an unhealthy ecosystem are those ecosystems which have poor biological sounds and high amounts of technology associated with them.
To learn more about Stuart Gage’s work, check out his blog, on pulseplanet.com.
Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation. I’m Jim Metzner.