What would the world sound like without humans in it?
 
You know about water contamination and particulate matter and carbon dioxide - but there's another kind of pollution. Scientists have been whispering about it for years. (Listen up.)

It's called biophony: the equivalent of the Golden Ratio for Planet Earth's acoustics. Twittering, as it were, is not just for the birds. Species around the world inhabit finely-orchestrated ecosystems, creating a synergistic symphony with all manner of chirps, tweets, croaks, and barks. These  vocalizations are necessary to survival. A round of ribbits from an army of frogs will foil a predator. But when a jet roars overhead, upsetting the chorus, the first confused frog to start croaking again is...lunch. Now spread that discordance across species, across the globe.

Bernie Krause, a leading bioacoustics scientist, believes that animals have evolved a "sonic niche" to fit their ecosystem and human-made disturbances to this harmonic soundtrack are putting many species at risk.

From the New York Times: "Many animals...have evolved to squeeze their vocalizations into available niches of the soundscape in order to be heard by others of their kind. Evolution isn’t just about the competition for space or food but also for bandwidth. If a species cannot find a sonic niche of its own, it will not survive."

With 40% of the planet - from the thickest forest in the Amazon to the vast stretches of the Arctic - contaminated by human-made noise pollution in the form of so many vehicles, aircraft and motorized toys, the acoustic balance of whole ecosystems is threatened. From whales to wolves to indicator species like frogs, biophonic corruption is interfering with communication. The effects are devastating to animal reproduction, migration, feeding, socialization and, ultimately, survival.

What we need is less noise, more signal.

Image: Aussiegall