Acoustic ecology in urban design

Building a healthy listening environment is important, and architectural intervention can help, writes Ritwik Kaikini

Spaces speak to us in different ways. Each environment has its own set of associated sounds that make us ‘sync’ with it in our unique ways. The more we are exposed to sounds from a particular space, the more domesticated it becomes. When we speak or listen within a given closed space, different types of reflections of sound waves within the space help us locate our bodies. 

Sensing spatial attributes by listening needs no extra effort since all of us are genetically hardwired to do it. The tapping sounds of our shoes on cement floors provide navigational confidence when walking inside a building. When we wake up in an urban city, the ‘gutargoo’ (cooing) of the pigeons, the distant hum of traffic, and the melodic practice of a neighbour’s classical music could be the first cues to locating ourselves in our home. Once these sounds enter our minds, we subconsciously decipher that we are inside an apartment facing away from a main road, where the window overlooks a large tree. Similarly, when we wake up in a village, the cock-a-doodle-doo of a rooster, ringing bells from moving cows, and the splash of the pail dropping into the well can be sonic cues to situate ourselves in a hut located in a paddy field. In both these situations, there is a difference in the way humans and other species build a relationship with the natural surroundings through sound. The study of this relationship is referred to as acoustic ecology.  

Changing sounds

The sounds that append our sonic dictionary, as we are raised in various surroundings, change over time, due the imposition of human-made or natural changes. In an anthropocentric perspective, the evolution of the aural architecture around us leads to a lot of behavioural, cognitive, and societal changes. For example, we tend to lose our voices after being inside a noisy nightclub with a group of friends, and we tend to feel anxious inside an anechoic chamber devoid of the most subtle sound. 

Similarly, in the animal kingdom, different species struggle to cope with the ever-changing acoustic landscape in urban spaces, which try to make humans the ‘centre of the lived experience’ rather than facilitate a harmonious co-existence. On one side, there is the widely known tangible interference with the natural habitat of species through prolonged events like the impingement of plastic on land, oil spillage in the oceans, and uncontrolled tapping of natural resources. On the other side is the intangible interference of acoustic environments faced by species native to a region. This unwanted noise can interfere with mating calls between species, interrupt circadian rhythms, and force constant habitat migration. As urban spaces around us get noisier, what happens to the melodious bird songs of the morning? 

In the short documentary film ‘Kiatsu: The Sound of the Sky Being Torn’ (2011), anthropologist Rupert Cox explores how a farming community struggles with the presence of a large Japanese airport. He brings to the forefront the harrowing violations of a pristine natural soundscape by recording sounds from the daily life of the last farming family living within the vicinity of a large airport. The tremendous noise of planes taxiing, taking off, and landing causes a huge ecological imbalance, affecting the harvest of crops as well as the well-being of the farmers on the land. 

In the Oscar-nominated documentary ‘All that Breathes’ (2022) by  Shaunak Sen, two brothers running a bird rescue clinic in Delhi claim that the animals have adapted much better to the human world than humans themselves because of their fearless experimentation.  

In an increasingly industrialised world, it is difficult to restore original natural soundscapes within urban spaces. However, in the interiors or exteriors of our homes, smart architecture and urban design can mitigate these noises, restore a balanced acoustic ecology, and create harmonious living environments.  

Diffusing noise

Ankit Bhargava, co-founder of the Sensing Local Foundation, an ‘Urban Living  Lab’ (ULL) based in Bengaluru, says that trees and bushes, along with landscapes at varying heights for multi-storey buildings, are key to absorbing or diffusing urban noise. When it comes to home interiors, the lack of insulated or sealed windows leads to noise, and architects build screens, partitions and walls to cut ground-level or directional noise. The choice of materials determines acoustic absorptive capacities. The world is getting hotter by the day, and the increase in the use of air-conditioners has added to the existing external noise.

In terms of alternatives to cooling,  Ankit says the architecture industry can use passive cooling techniques using the Venturi effect. Courtyards are a good solution, as is cleverly designing wind flow in a room or house. However, these practices are being neglected, since everyone is trying to maximise built space. When it comes to restoring a natural soundscape in urban spaces, Ankit says reducing vehicles and reclaiming the streets for walking and cycling can bring massive benefits to humans and biodiversity. Other ideas like slow streets and pedestrian streets can also be deployed selectively.  

Technology plays a huge role in our aural relationship with the environment. As noise levels rise, our ears become accustomed to the new noise floor and our perception of ‘silence’ is disturbed. As natural sounds wither away, our ears tend to absorb less information about the natural environment affecting our aural vigilance. With a dwindling attention span, the room for silent thought shrinks, inviting us to fill our silent gaps of time with music. The use of earphones further disturbs our listening capacities. Hence, multiple factors play a role in creating a healthy listening relationship with our environment and preserving the same amidst other species. 

Through effective urban design, silence and natural sounds must be given their rightful place to restore an eco-acoustical balance and propagate healthier listening cultures.