Rethinking environmental noise assessment through a noise footprint framework

1 A need to incorporate noise in environmental footprinting

A significant body of research across the world [1] assesses the impacts of noise on human health [2] and emphasizes the need for increased attention [3]. New technologies on noise prediction [4] and the establishment of methods to measure soundscapes [5] introduced fresh perspectives to link noise (or sound) to human well-being. A linear description of this phenomenon typically involves a source producing a quantifiable amount of sound power, resulting in pressure at the receiver point [6]. Unfortunately, the aforementioned interaction is not always linear and most importantly, it could be asynchronous. Noise impacts may not necessarily be direct, as research has identified long-term consequences for human and environmental health [7] in a variety of spatiotemporal scales and conditions [8].

It is meaningful to move beyond linear boundaries and geographical constraints in noise assessment by considering the total noise generated across all phases of systems such as products, processes, services, activities, and personal choices. The acoustic impacts of tangible goods throughout their entire life cycle should be evaluated from a cross-sectoral perspective, recognizing that individual consumer choices ultimately influence human health, environmental quality, and other key assessment endpoints. With this growing knowledge, we have the potential to do much more. A significant advancement in noise assessment would be the adoption of a holistic, responsibility-based framework that moves beyond direct source–receiver interactions and acknowledges the complex interdimensional and spatiotemporal dynamics of noise.

The concept of an environmental “footprint” is highly relevant in this context. While there is no universal definition of “footprint” [9], it is generally understood as a quantitative measure of the potential impacts caused by a product, service, or organization throughout its entire life cycle [10].

Several approaches regarding the calculation of carbon footprint [11], water footprint [12], and energy footprint [13] have been developed. Among these, the carbon footprint has played a particularly influential role in advancing environmental protection, guiding informed decision-making, and promoting social engagement, especially in the context of climate action and lifestyle changes [14].

Since sound environments and their perceptual construct, the soundscape, are recognized as resources that must be protected and managed sustainably [15], the development of a noise footprint framework is therefore both valuable and necessary.

The calculation of the total noise generated by all relevant sources within a process, under a noise footprint framework, could promote noise-aware citizens, positive soundscapes, and overall quieter environments, similarly to how carbon footprints aid in identifying and reducing environmental impacts. To achieve this, alongside a clear definition and scope, a noise footprint indicator reflecting the cumulative acoustic pressure exerted on human and environmental receptors will be developed.

Nevertheless, the above is not without potential misconceptions. In the context of noise, the notion of a noise footprint can be loosely linked to the spatial extent of noise propagation, often visualized through noise mapping. However, this spatial interpretation may oversimplify the multidimensional nature of noise impacts. Even though undeniably useful to urban planners, governments and regulatory bodies for identifying “noise hotspots” and highlighting limit breaches, affected populations, and exposed dwellings within a specific area, noise maps represent only a snapshot in time. They stand as a static picture that indicates where noise levels from a single or a combination of sources are high, whilst a noise footprint can be comparable across products, services, or lifestyle choices, supporting more targeted and effective mitigation strategies. To this end, noise footprinting could work alongside strategic noise mapping but serving a different purpose.

In order to make the future noise footprint process more effective and help create a robust and consistent methodology for its calculation, a set of key elements underlying methodological and policy aspects are suggested.

2 A call to action

The introduction of a noise footprint framework, aligned with other environmental footprints such as the carbon footprint, offers an alternative approach to assessing environmental noise, shifting from isolated measurements to a holistic view that captures cumulative impacts across life cycles and sectors.

This framework will involve the development of original metrics to quantify the cause-effect chain linking noise emissions to their impacts. Given the complexity of this chain, the focus should be on the intermediate/midpoint stage, assessing decibel-based indicators that characterize the physical properties of noise pollution. However, physical measurements alone cannot capture the full spectrum of effects on human health.

As the regulatory landscape in noise action plans evolves, showcased by recent initiatives in Wales that embed the soundscape approach [22], there is a timely opportunity to advance noise assessment by incorporating more holistic and perceptual dimensions.

It will be beneficial to incorporate in the noise footprint the perceptual dimension by integrating psychoacoustic metrics [23] and Soundscape Perception Indices [24], which reflect how noise is experienced and interpreted by individuals compared to specific targets.

As noise pollution is linked to consumption-based emissions across personal, product, organizational and city-level activities, bottom-up footprinting approaches similar to carbon footprint calculators [25] can empower citizens, inform more effective policies and result to more livable environments [26].

This effort will be further strengthened by the introduction of a noise footprint calculator designed to measure and communicate the environmental impacts of noise. Increasing awareness of individual contributions to noise pollution can motivate people to take meaningful action, enabling them to develop their own solutions to mitigate noise-related problems.

Access to a tool informing on the individual’s contribution to noise pollution could produce motivation and create a sense of moral obligation, hence reinforcing citizenship and social responsibility. For example, understanding the noise impacts of a product throughout its life cycle and not just during the use phase could encourage better choices, improving soundscapes beyond the user’s immediate audible sphere. Nevertheless, individual actions and lifestyle alterations alone are not enough to cause a desirable change. Greater accountability and transparency regarding noise-related information from larger institutions and authorities are essential to support healthier sound environments and sustain positive behavior change.

To achieve this, a wide range of interventions and activities will be implemented to refine the noise footprint. These, amongst others, will include assessments in the building sector, such as evaluating the impacts of noise-producing equipment, as well as analyzing the total noise generated throughout the entire life cycle of a product, from material extraction and transportation to use and disposal.

We invite the noise research community, policymakers and stakeholders to collaborate in refining this concept, developing robust methodologies, and integrating noise footprinting into environmental policy.