A quantitative and qualitative review of amplitude modulation noise from wind energy development.

The adverse impact of amplitude modulation (AM) has been acknowledged in research, papers, and anecdotal evidence since at least 2002. Only in 2013, in the UK, did wind industry acousticians finally acknowledge the common impact of AM and the need for control. Some still deny the need for control at public inquiries. Despite two independent bodies, the Institute of Acoustics (IoA) and the Independent Noise Working Group (INWG), announcing a review of AM from a planning perspective in 2014 and the UK Government's DECC commissioning further review of AM in 2015 the UK is still, at the time of writing, without any unanimous and / or accepted guidance for assessing and conditioning AM at the planning stage. This paper reviews a range of metrics and methods that have been proposed and their ability to work with real world data. This paper questions whether a "one size fits all", purely quantitative approach reflects subjective AM impact and provides initial findings of a preliminary study testing whether different manifestations of AM can be considered equal.