I’ve been looking out the window a lot these day, watching the sky for the small daily changes in clouds and bird movements. Considering how much our lives have changed these past few weeks the view out my window seems to look much the same. But one change I’ve noticed is the sound. It’s not silent, but the volume has definitely been turned down.
Seismologists have tracked the change as the Earth’s surface has been vibrating less (due to reduced human movement and activity). Cars, planes and even walking make tiny vibrations in the ground, and as these movements are reduced the seismic activity in cities such as Brussels has reduced by about 30 to 50 percent.
Reduction in noise can have far-reaching impacts. Studies have shown that traffic noise reduces bats’ ability to feed while some male birds are trying to compete with traffic and city sounds by singing louder and at increasingly higher frequencies, which could harm their vocal cords and hearing. The change in the latter is causing a city-country divide, says Dr Sue Anne Zollinger of the University of St Andrews: ‘The difference between urban and rural birdsong is becoming so great that the two groups could now be unable to communicate, leading to inbreeding and a weakened gene pool’.
But while the sound of cities has reduced, giving nature a moment to breathe more easily, are the cities really so silent? The idea of silence can be relative, as shown by the ‘silent’ recording of a blue whale in the British Library. As artist Vibeke Mascini explores through the Delfina Foundation’s 2020 residents projects, while the whale’s song is lower than our human ears can perceive it has a world of meaning we simply can’t hear. Mascini explains ’Of course sound is not merely a sonic experience to whales, it is part of an entire constellation of senses corresponding with phenomena beyond our wildest notions. Sound is also a visual experience, it is known that by emitting and receiving sound frequencies whales can visualise shapes and marine landscapes thousands of miles away.’
But it seems that excessive noise is not just present in our cities, it has made its way into the ocean too, leading to multiple whale-strandings and posing a threat to thousands of ocean creatures. The delicate balance of noise under the seas is something we have only recently started to understand and scientists are in a race to map ocean noise in a bid to dial down the volume.
I was thinking about all the sounds we can and can’t hear on International Dawn Chorus Day on 3 May, as #Reveil2020 followed the dawn around the world. It reminded me of a ballet class I had once when I was a kid – the power had gone out and the teacher still had to entertain us for another 45 minutes before we got picked up (in the days before mobiles!). So she got us to lie on the floor and listen to the night; listening further and further out past the initial rumble of cars into a surprisingly layered soundscape.
What sounds have changed for you these days? What have you been listening out for?