The world now sounds different to how it did a century ago

We have triggered animal extinctions and climate change, and both have altered the way our world sounds

You can hear the climate changing. As the world warms, the soundtrack of the ocean is shifting.

In 2015, a US team of scientists and engineers reported that the loudest sound in some waters now comes from millions of tiny bubbles, which are released by melting glaciers and icebergs. In the fjords of Alaska and Antarctica, the average noise level is now over 100 decibels – louder than any ocean environment recorded before.
This is just one example of how Earth’s natural soundscape is changing irreversibly, and human activity is driving the process.
Our natural spaces are now polluted with human-made noises. As we change forests into farms and drive species to extinction, we are fundamentally changing how our world sounds.
The phenomenon has inspired a new field of research, which aims to monitor the changing melody of our natural spaces. These acoustic studies could revolutionise the way we study whole ecosystems, from forests to coral reefs.
All the sounds of an ecosystem – from trickling streams to singing birds – add together to form a unique soundscape; a fingerprint of the habitat in its current state. Studying a soundscape is a quick and easy way to get an overview of the health of a habitat.
Shrimp snaps are one of the most characteristic sounds of marine ecosystems 
But what scientists are hearing is not good. Some soundscapes are deteriorating in an alarming way.
Oceans in particular now sound very different. As the noise from melting glaciers rises, the sound produced by some marine species is falling.
For as long as biologists have been studying the seas, snapping shrimps have been creating a din. Each snapping shrimp has an asymmetrical, oversized claw, which it can snap shut at up to 60mph. This temporarily forms an air bubble in the water, and when this pops it forces water out in a high-pressure jet and produces a loud snapping sound.
These snaps are thought to be important for communication, as well as to stun prey and scare off predators.
Shrimp snaps are one of the most characteristic sounds of marine ecosystems like mangroves and coral reefs. They can travel up to a kilometre through the water. But a study published in March 2016 suggests the shrimp might soon fall silent.
As climate change continues to alter marine ecosystems, we might find our oceans go quiet 
Biologists recorded sound at three hydrothermal vents, where carbon dioxide is naturally released into the water. Carbon dioxide forms a weak acid when it reacts with water, lowering ocean pH. This “ocean acidification” is now happening throughout the oceans because of the extra carbon dioxide in the atmosphere. The hydrothermal vents give scientists a chance to study what a more acidic ocean might be like.
They found it might sound a lot quieter. Shrimp around the vents snap less loudly and less often than expected, drastically changing the overall soundscape of the ocean. When tested in the lab under elevated carbon dioxide levels, individual snapping shrimp produced half as many snaps as those kept at current levels.
Although it remains unclear exactly why it silences snapping shrimp, widespread acidification could have a major impact on coral reef species that rely on sound for navigation. As climate change continues to alter marine ecosystems, we might find our oceans go quiet.
Scientists have divided the acoustic world into two groups. There is “geophony”, which comes from natural processes like crashing waterfalls, the movement of the tides and the rumble of earthquakes – and then there is “biophony”, which is produced by living things.
Human-made noises have become so ubiquitous on Earth that we have come up with a third category just for them: “anthrophony”. In many landscapes, anthrophony dominates, drowning out the sounds of nature.
Studying a soundscape is a quick and easy way to get an overview of the health of a habitat 
Human sounds are now found in almost every ecosystem on Earth, and it is rare to find an area remote enough to avoid human sounds entirely. But Michael Scherer-Lorenzen of the University of Freiberg in Germany says that our indirect effect on soundscapes has been even stronger. Sounds are slowly and subtly being lost as habitats become increasingly fragmented, species become extinct and urban landscapes expand.
This is an idea that Scherer-Lorenzen and his colleagues are exploring as part of one of the most ambitious studies in soundscape ecology undertaken to date. Beginning in September 2015, the researchers have left 300 microphones recording in the German countryside. The aim is to find out how different types of land use affect biodiversity, and how this is reflected in the soundscapes of those habitats.      — BBC

The world now sounds different to how it did a century ago

We have triggered animal extinctions and climate change, and both have altered the way our world sounds

You can hear the climate changing. As the world warms, the soundtrack of the ocean is shifting. In 2015, a US team of scientists and engineers reported that the loudest sound in some waters now comes from millions of tiny bubbles, which are released by melting glaciers and icebergs. In the fjords of Alaska and Antarctica, the average noise level is now over 100 decibels louder than any ocean environment recorded before. This is just one example of how Earths natural soundscape is changing irreversibly, and human activity is driving the process. Our natural spaces are now polluted with human-made noises. As we change forests into farms and drive species to extinction, we are fundamentally changing how our world sounds. The phenomenon has inspired a new field of research, which aims to monitor the changing melody of our natural spaces. These acoustic studies could revolutionise the way we study whole ecosystems, from forests to coral reefs. All the sounds of an ecosystem from trickling streams to singing birds add together to form a unique soundscape; a fingerprint of the habitat in its current state. Studying a soundscape is a quick and easy way to get an overview of the health of a habitat. Shrimp snaps are one of the most characteristic sounds of marine ecosystems But what scientists are hearing is not good. Some soundscapes are deteriorating in an alarming way. Oceans in particular now sound very different. As the noise from melting glaciers rises, the sound produced by some marine species is falling. For as long as biologists have been studying the seas, snapping shrimps have been creating a din. Each snapping shrimp has an asymmetrical, oversized claw, which it can snap shut at up to 60mph. This temporarily forms an air bubble in the water, and when this pops it forces water out in a high-pressure jet and produces a loud snapping sound. These snaps are thought to be important for communication, as well as to stun prey and scare off predators. Shrimp snaps are one of the most characteristic sounds of marine ecosystems like mangroves and coral reefs. They can travel up to a kilometre through the water. But a study published in March 2016 suggests the shrimp might soon fall silent. As climate change continues to alter marine ecosystems, we might find our oceans go quiet Biologists recorded sound at three hydrothermal vents, where carbon dioxide is naturally released into the water. Carbon dioxide forms a weak acid when it reacts with water, lowering ocean pH. This ocean acidification is now happening throughout the oceans because of the extra carbon dioxide in the atmosphere. The hydrothermal vents give scientists a chance to study what a more acidic ocean might be like. They found it might sound a lot quieter. Shrimp around the vents snap less loudly and less often than expected, drastically changing the overall soundscape of the ocean. When tested in the lab under elevated carbon dioxide levels, individual snapping shrimp produced half as many snaps as those kept at current levels. Although it remains unclear exactly why it silences snapping shrimp, widespread acidification could have a major impact on coral reef species that rely on sound for navigation. As climate change continues to alter marine ecosystems, we might find our oceans go quiet. Scientists have divided the acoustic world into two groups. There is geophony, which comes from natural processes like crashing waterfalls, the movement of the tides and the rumble of earthquakes and then there is biophony, which is produced by living things. Human-made noises have become so ubiquitous on Earth that we have come up with a third category just for them: anthrophony. In many landscapes, anthrophony dominates, drowning out the sounds of nature. Studying a soundscape is a quick and easy way to get an overview of the health of a habitat Human sounds are now found in almost every ecosystem on Earth, and it is rare to find an area remote enough to avoid human sounds entirely. But Michael Scherer-Lorenzen of the University of Freiberg in Germany says that our indirect effect on soundscapes has been even stronger. Sounds are slowly and subtly being lost as habitats become increasingly fragmented, species become extinct and urban landscapes expand. This is an idea that Scherer-Lorenzen and his colleagues are exploring as part of one of the most ambitious studies in soundscape ecology undertaken to date. Beginning in September 2015, the researchers have left 300 microphones recording in the German countryside. The aim is to find out how different types of land use affect biodiversity, and how this is reflected in the soundscapes of those habitats. BBC