Irwin Carr welcomes the publication of the updated Assessment and Rating of Wind Turbine Noise, which represents a positive and practical step forward for the assessment of wind turbine noise across the UK and Ireland.

While the fundamentals of ETSU-R-97 remain familiar, the replacement document provides much-needed clarity in several key areas that have historically been subject to interpretation in planning and appeal decisions. 

Clearer Approach to Amplitude Modulation (AM) 

A notable improvement is the more structured treatment of amplitude modulation (AM). The updated guidance provides clearer definitions of what constitutes AM, introduces a more consistent framework for identifying and assessing AM effects, and supports a more proportionate and evidence-based response where AM is confirmed. 

Better Definition of “Special Characteristics” 

The revised ETSU also strengthens the guidance surrounding “special characteristics” of wind turbine noise, such as tonality, impulsivity and other perceptible features. More explicit criteria are provided for identifying these characteristics, alongside improved guidance on when and how penalties should be applied. 

Supporting Balanced Decision-Making 

Overall, the update brings a clearer, more robust framework for assessing wind turbine noise, reducing reliance on subjective interpretation and improving confidence in outcomes. Irwin Carr believes these improvements will benefit both developers and residents, providing greater certainty in the planning process while ensuring that genuine noise effects are appropriately identified and managed.