The human world is getting louder. The non-human one struggles to be heard

It is Diwali night in India. Firecrackers explode across neighbourhoods, incessantly. The sky is illuminated with colours. People celebrate. Children cheer at every burst of light and sound. Beneath a Tagar (Pinwheel flower) plant lies a crow. Its eyes are half closed. Two or three flowers have fallen on it. The bird is dead. Nobody seems to have noticed.

There is nothing extraordinary in the frame. What could be more natural than the death of a bird in a human world?

We do not know what killed this crow. We will probably never know. Yet its presence raises an unsettling question: what happens to the creatures that share our cities when the sounds of human life become impossible to escape?

While noise pollution is often discussed in relation to public health, the impact it can have on wildlife is often overlooked. However, a significant study published in Science on 5 November 2026 shows that the damage being caused is much greater than previously thought.

The whole human world grows cacophonous, incessantly.

Aircraft engines, road traffic, construction machinery, industrial compressors, boats, sonar underwater, and seismic surveys have made our planet much louder. Fireworks also cause sudden loud noises.

A study by researchers Hansjoerg Kunc and Rouven Schmidt from Queen’s University Belfast looked at 214 studies. They looked at 177 species of both terrestrial and aquatic animals across 97% of countries in the world.

The finding is alarming. 80% Of species had at least one biological or behavioral change due to noise.

This caused a range of issues such as changes in reproduction, immune system, breathing, movement and feeding. There was also a decline in the abundance of animals by approximately 40% in habitats exposed to human-generated noise. Animal mortality rose by almost 140%. Noise is causing animals to experience severe physiological stress.

Changing how birds sing

Birdsong is not only beautiful but also informative. Birds use songs to attract mates, defend their territory, alert others to predators and communicate with their chicks.

However, the noise we make can affect this process. This is known as acoustic masking. Traffic and machinery can cause noises similar to the birds'. This can make it difficult to hear the important messages.

Some birds have adapted by singing at a higher frequency. Some have increased the length or loudness of their songs. A study of two closely related vireo species in New Mexico showed that even within the same genus birds may sing differently.

However, this can cause problems. Singing at a higher pitch can make the birds less attractive to mates. Longer songs will also require more energy. Communication can become more difficult.

Some urban birds have even changed their songs to sing at night.

When the night hunters cannot hear

Nocturnal birds rely heavily on sound to hunt. Owls listen out for quiet noises and rustling to find their prey. However, traffic can cause acoustic masking. This makes it harder for them to navigate their hunting grounds. Research has found that owls struggle to hunt due to traffic noise. They cannot find their prey as easily.

Noise can disrupt the delicate balance between predator and prey, making it difficult for some animals to hunt and others to sense approaching danger. The mouse or small animal may not be spotted due to the background noise. This causes the predator to waste time and energy. Research done in the backcountry of Yellowstone found that aircraft noise could reduce the area a predator could hear their prey by up to 70%. Some birds have adapted to avoid the noise during the day by singing at night.

The hidden crisis inside a nest

When noise affects the developing chicks

A study published in Science looked at zebra finches exposed to moderate traffic noise. The eggs were exposed to road noises for five nights in a row. The chicks were then exposed to noise during their early development.

The results were alarming. On average, the eggs were 19% less likely to hatch when exposed to traffic noise compared to birdsong. Those that did hatch were slower growing, had fewer red blood cells and signs of cellular stress.

Those exposed to noise produced around half as many offspring as those exposed to birdsong.

Parents can also be affected.

A study published in PeerJ in 2024 looked at Western bluebirds. It was found that short-term traffic noise caused the failure rate to increase by over six times. Parents may have gone to feed their chicks but failed.

However, some birds living in constant noise increased the amount of feeding they did. This may be due to changes in perceived predation risk or due to physiological changes.

Noise causes animals to change fundamental behaviours to survive.

Kites in Delhi are learning to adapt

Another way to understand this changing relationship is through Shaunak Sen’s documentary All That Breathes.

It follows Nadeem and Saud, two brothers who save black kites in Delhi. The brothers have observed how the kites adapt to their increasingly hostile environment. The kites have adapted to living with humans. They are becoming louder with higher-pitched calls. This documentary is important as it shows how the animals are living with us on a daily basis. However, the conditions they are living in are changing.

Just because they are adapting doesn’t mean they are thriving.

The ocean is losing its calm

Ships, offshore construction, sonar from the military and seismic air guns all create loud noises in the marine environment. Sound travels further and faster in water. Whales and dolphins use sound to communicate, navigate and find food. This can be masked by noise in the water. This can affect their echolocation. Exposure to sonar has been linked to behavioral changes in whales. Seismic surveys can cause serious injuries. Crabs and lobsters may leave their shelters which makes the ship noise louder. This can put them in danger from predators.

Ecological imbalance

Noise can cause changes in who eats whom, who can escape and who can reproduce. Bats hunting moths struggle to find their prey. This means they use more energy to catch less food.

The latest analysis from Science found that predators had to work 2.5 times harder to catch around a quarter less prey.

This can cause changes in the whole food web. Some species will benefit from the changes. However, others will struggle to find food. Noise can also cause animals to move away from certain areas. Some will avoid areas with noise, whereas others will stay but change how they communicate and feed.

Over time this can cause changes in populations and the balance between species.

Making room for other voices

Scientists argue that we cannot just protect forests, wetlands and oceans. We need to protect the soundscape. Using electric cars and quieter ships can help reduce some of the disturbance. Creating low noise areas and acoustic sanctuaries can help give animals a place to communicate and reproduce. Current regulations regarding underwater noise need to be enforced more. More research needs to be done to find out what exact noise levels affect different species.

Overall, it is clear that we are not just changing the landscape but also the sensory world animals have evolved in. While we may never find out what happened to the crow under the Tagar (Pinwheel flower) that night, it is important to remember that it was there. The world can be full of life but it can become increasingly difficult for those living in it. Maybe the next great challenge in conservation will be giving wildlife back their voice.