Monitoring Edmonton’s soundscape
Urban noise can have detrimental effects on both human health and biodiversity. In 2025, we began a pilot project to assess noise in Edmonton’s natural areas and its effects on both human and non-human city dwellers. This project is in collaboration with the Edmonton Valley Zoo, City of Edmonton and the University of Alberta as we welcomed Martin Hinojosa, a U of A Sustainability Scholar, to the project for the summer!
What’s all the noise about noise?
Noise pollution both reduces habitat quality for species and affects the quality of life for city residents.
The World Health Organization (WHO) considers noise an underestimated threat to human health. Noise pollution, unwanted or harmful sounds generated by human activity, is linked to higher stress, sleep disruptions, and decreased performance in school by children. A part of sustainable urban planning is mitigating urban noise for the benefit of residents. For instance, the WHO has guidelines for noise levels at night and near schools.
Habitat quality is also linked to noise levels: species need to be able to hear each other for communication, reproduction, and survival and noise pollution can make all these things more difficult. Some bird species have been found to change the frequency and timing of their songs in noisy urban areas, while some avoid noisy areas altogether. Adaptation takes time, and not all species may be this flexible.
Noise pollution (or lack thereof) is influenced by both the size of a natural area and its location within the urban environment. This project aims to assess the proportion of Edmonton that exceeds noise sensitivity thresholds for both people and biodiversity, mapping these thresholds to inform future urban planning decisions.
Our monitoring sites
In 2025, we established over 100 bioacoustic monitoring sites. Sites were spread across a wide range of land-use types, including residential, commercial, industrial, and recreational areas. Sites also varied in proximity to noise sources such as major roads and railways. From pocket parks to forested ravines to the zoo, our aim was to capture the full variety of soundscapes within Edmonton. Many of these sites built off previous research using wildlife cameras and lichens as biomonitors.
In the spirit of noise reduction, the team travelled to the monitoring sites by bike. In total, we pedalled over 1,900 km over the summer—the equivalent of biking the Silk Road Mountain Race in Mongolia! Travelling by bike also reduced the project’s greenhouse gas emissions, saving an estimated 0.5 tons of carbon.
We collected acoustic data using autonomous recording units (ARUs), with a mix of Wildlife Acoustics Song Meter SM4 and SM Mini 2 equipped with stereo-microphone stubs. The ARUs were programmed to capture sounds throughout the day and during critical periods such as dawn and dusk. A subset of the ARUs were paired with decibel meters to measure sound pressure. We also installed two ARUs capable of recording animals that communicate ultrasonically… aka bats! Overall, almost 50,000 recordings were collected over the summer, paired with 3 million decibel readings.
Autonomous recording units (ARUs) are passive, non-intrusive sensors that can be left out for long periods of time to record wildlife and background noise
Turning decibels into decisions
We processed the recordings using WildTrax, an online platform for managing data from environmental sensors such as ARUs. In each recording, we analyzed the full acoustic community, including birds, mammals, and amphibians, as well as environmental noise (i.e., wind, rain and noise from human activities) present at different times of day.
Using data from the decibel meters, we built noise maps for the city for different time periods and days. We then compared the noise maps to species distribution maps built using the analyzed recordings as well as to information such as road density, elevation, and population density to understand drivers of noise and how species respond.
Unsurprisingly, some species responded negatively to noise. Wooded natural areas support unique species communities that were also most sensitive to increased noise: these areas saw the steepest declines in biodiversity as noise levels increased.
Interesting species heard include Barred Owl, Canadian Toad, Nelson’s Sparrow, and Mourning Warbler
Overall, the study found that over 90% of the city has nighttime noise levels that exceed WHO guidelines. These findings as well as the local drivers of noise levels (such as distance to arterial roads) will be essential for both informing urban planning and monitoring the effectiveness of noise mitigation measures such as noise barriers, speed limits, and zoning.
All together, this data will help us understand what species are where and establish noise thresholds to guide sustainable urban planning decisions. How loud is too loud for biodiversity? Where are noise thresholds too high for human health and well-being?