Hearing the Turbines: Wind Energy and Changes to Rural Soundscapes 

By Eugene McKeown, Eoin King and Denis O’Hora. Galway Sound Lab, University of Galway.

For acousticians working on wind energy projects, compliance with regulatory limits is only part of the challenge. Equally important is understanding how new sources of sound alter existing acoustic environments and how those changes are experienced by impacted communities.

Wind turbines have become a familiar part of rural landscapes, but wind turbine noise remains a contentious issue. Current practice is to demonstrate compliance with planning regulations, standards, or technical guidance such as the UK’s ‘Assessment and Rating of Wind Turbine Noise’ in the UK.

The UK and other international guidelines set wind turbine noise limits in the 35 to 45 dBA region, especially for night-time or in more mixed-use settings. A common approach is either a fixed limit such as 40, 43, or 45 dBA, or a background noise related rule such as 5 dBA above ambient sound levels. In rural landscapes (in Ireland) background noise levels are typically 35-45 dBA by day and lower at night. The daytime wind turbine noise turbine limit may therefore be close to existing background levels, making the change subtle but still noticeable. In quiet areas at night, background noise levels can drop below 25 dBA which sits well below the UK 43 dBA limit, so turbine sound could dominate and significantly increase perceived intrusion.

Wind turbine noise can be a steady broadband sound but sometimes it is characterised by amplitude modulation (AM). AM is a rhythmic “swish” or “thump” that draws attention even at relatively low levels. Research consistently shows that amplitude-modulated sound is more annoying than other environmental noise at the same level because it is more noticeable [1].

Noise from wind turbines is also highly variable. Long range audibility depends on wind shear, atmospheric stability, terrain, and turbine operating conditions. At night, under stable atmospheric conditions, sound can travel further and be perceived as more prominent. This variability is difficult to capture in simplified prediction models, which often assume steady-state conditions and average meteorology.

Regulatory Framework

Existing regulatory frameworks offer a consistent basis for assessment, but they do not capture how residents experience and respond to changes in their acoustic environment. Equally important is the preservation of amenity in settings where tranquillity is itself part of the character, such as national parks. Low levels of anthropogenic noise have been shown to support both ecological integrity [2] and human well-being [3]. Natural soundscapes allow species to communicate, forage and reproduce effectively and offer psychologically restorative experiences for visitors.

Distant noise sources such as air overflights, major roads, industry and renewable energy infrastructure can be audible for considerable distances across quiet landscapes. The addition of noise sources such a wind turbines, inverters, transformers and even smaller components such as cooling-fans subtly erode the acoustic character of quiet areas. This creates a tension between climate-change mitigation goals and the preservation of acoustic amenity.

National parks and rural areas are commonly valued for their relative quiet, but “quiet” is not silence [Directive 2002/49/EC]. Such areas have an existing soundscape with wind and nature sounds, distant agricultural sounds along with road, air and sometimes rail traffic sources. Wind turbines introduce a new and persistent sound source into this environment. Studies in Northern Europe have found that wind turbine noise is more annoying in quiet rural settings than in already noisy environments, suggesting that context matters as much as level [4].

This raises an ethical question of what constitutes an “acceptable” acoustic change in the context of energy transition? Renewable infrastructure delivers clear public benefits, yet those benefits are not evenly distributed. Some communities host turbines and experience their acoustic presence directly, while others benefit from the electricity without encountering the sound. The WHO Environmental Noise Guidelines underline that health and quality-of-life impacts are not uniform and that environmental justice must be considered in noise policy.

Independent acousticians occupy a mediating position. They interpret data for planners and developers but also listen to residents and visit sites under different conditions. Their role is not only to verify compliance but to ask whether compliance is enough. Important questions remain regarding the suitability of current limits in low-background-noise environments, the treatment of amplitude modulation, and the extent to which operational strategies can reduce perceptual impacts without materially affecting energy yield. There are no simple answers. Quieter blade designs, operational curtailment during sensitive periods, and more nuanced planning guidance can help, but they cannot eliminate trade-offs.

The acoustician must balance data, policy, and lived experience while acknowledging that not all impacts can be fully resolved. The challenge for an acoustician is to recognise that some impacts may remain, and that society must decide what level of acoustic change it is willing to accept in pursuit of decarbonisation.

Planning processes are more likely to command public trust when potential noise impacts are openly acknowledged and clearly communicated [5]. Communities living closest to wind energy developments will experience the greatest acoustic change. Transparent assessment methodologies, inclusive engagement processes and acknowledging the disproportionate burden borne by these communities are critical in the pursuit of public trust.

Listening, in this sense, is not just a technical skill. It requires us to hold both climate imperatives and local experience in view, and to be clear about what each demands.

References:

[1] Zajamsek, B., Hansen, K., Lechat, B., Liebich, T., Dunbar, C., Micic, G., & Catcheside, P. (2022). Annoyance due to amplitude modulated low-frequency wind farm noise: A laboratory study. The Journal of the Acoustical Society of America, 152(6), 3410–3421. https://doi.org/10.1121/10.0016499

[2] Farina, A., Krause, B., & Mullet, T. C. (2024). An exploration of ecoacoustics and its applications in conservation ecology. BioSystems, 245, 105296. https://doi.org/10.1016/j.biosystems.2024.105296

[3] Buxton, R. T., Pearson, A. L., Allou, C., Fristrup, K., & Wittemyer, G. (2021). A synthesis of health benefits of natural sounds and their distribution in national parks. Proceedings of the National Academy of Sciences, 118(14), e2013097118. https://doi.org/10.1073/pnas.2013097118

[4] Bolin, K., Kedhammar, A., & Nilsson, M. E. (2012). The Influence of Background Sounds on Loudness and Annoyance of Wind Turbine Noise. 98, 741–748. https://dael.euracoustics.org/

[5] Elmallah, S., & Rand, J. (2022). “After the leases are signed, it’s a done deal”: Exploring procedural injustices for utility-scale wind energy planning in the United States. Energy Research & Social Science, 89, 102549. https://doi.org/10.1016/j.erss.2022.102549

Authors Bio:

Eugene McKeown is a Galway-based soundscape researcher and facilitator at the University of Galway. His work explores listening, place, and environmental awareness, including guided soundwalks that encourage new ways of experiencing natural and urban soundscapes.

Dr. Eoin King is a Lecturer in Mechanical Engineering at the University of Galway and Director of the Galway Sound Lab. His research focuses on environmental acoustics, noise control, transportation noise, and the role of sound in sustainable urban design.

Denis O’Hora is an experimental psychologist and behavioural scientist in the School of Psychology in University of Galway. Denis studies the dynamics of learning and decision making; that is, how we interpret, respond and adapt to the situations we find ourselves in.