Wind Farm Noise and Human Perception: A Review
Robert Thorne, PhD of Noise Measurement Services|February 1, 2014
This important report prepared by noise acoustician, Robert Thorne PhD of Noise Measurement Services in Australian, provides a comprehensive explanation of our "state of understanding" regarding wind turbine noise and the effects of the noise on communities. This report is updated from a previously released version of Dr. Thorne's study.
This important report prepared by noise acoustician, Robert Thorne PhD of Noise Measurement Services in Australian, provides a comprehensive explanation of our "state of understanding" regarding wind turbine noise and the effects of the noise on communities. This report is updated from a previously released version of Dr. Thorne's study.
Preface
There is significant body of peer-reviewed research readily available in the public forum to substantiate the potential for serious to moderate adverse health effects to individuals due to wind farm activity noise while living in their residences and while working on their farms near large-scale wind farms or large turbines. Adverse health effects can arise from extreme psychological stress from environmental noise, particularly low frequency noise with symptoms of sleep disturbance, headache, tinnitus, ear pressure, dizziness, vertigo, nausea, visual blurring, tachycardia, irritability, problems with concentration and memory, and panic attack episodes associated with such sensations when awake or asleep.
The hypothesis from this Review is that serious harm to health occurs when a susceptible individual is so beset by the noise in question that he or she suffers recurring sleep disturbance, anxiety and stress. Research for the Review suggests that 5% to 10% of the individuals living in the vicinity of a large wind farm will experience serious harm to their health. The observed markers for serious health effects are
(a) wind farm noise level of LAeq 32 dB or more outside the residence and
(b) wind farm noise is heard or is perceptible (felt) at levels above the individual's threshold of hearing inside the home
Meteorological conditions, wind turbine spacing and associated wake and turbulence effects, vortex effects, wind shear, turbine synchronicity, tower height, blade length, and power settings all contribute to sound levels heard or perceived at residences. Wind farms are unique sound sources and exhibit special audible characteristics that can be described as modulating sound or as a tonal complex. Current noise prediction models are simplistic, have a high degree of uncertainty, and do not make allowance for these significant variables. Compliance monitoring must therefore include continuous real-time measurement of characteristics such as modulating sound in order to determine the perceptible effects of audible sound and inaudible infrasound.
The Review contains references to the Noise Measurement Services (NMS) research, measurements, and observations at different wind farms in New Zealand and Australia. All NMS research including the study methodologies are peer-reviewed. Such work is commercial-in-confdence to NMS and of a confidential nature to the participants.
No datasets, apart from those presented in this Review, are disclosed or publicly available.
Table of Contents
PART I - INTRODUCTION
Inappropriate Land-use Planning
The Problems with Wind Farm Noise and Its Perception
Ineffective Compliance Approvals
PART II - A CASE STUDY
A Rural Wind Farm
Prediction of Wind Farm Sound Levels
Predictions and assessments – An example with a Waubra residence
Background sound levels
The Effects of Weather
Audible sound character
Sound character at residence and near locale
Conclusions from Waubra Case Study
PART III - WIND FARMS AND HEALTH EFFECTS
PART IV - WIND TURBINE SOUND
Basic Measures
Wind Farm Noise
Low frequency sound and Infrasound
Heightened Noise Zones
PART V - PREDICTION OF SOUND LEVELS – APPROACHES AND LIMITATIONS
Consideration of Variable Wind Conditions
Consideration of ‘Stand-Off distances between Turbines and Residents’.
Wind Farm Noise` Standards
PART VI - RESPONSES OF RESIDENTS NEAR WIND FARMS
Community and Individual Noise Exposure
Noise Measurement Services Pty Ltd Wind Farm Noise Review April 2013
The Effects on People near the Waubra Wind Farm, Victoria
The Effects on People near the “West Wind’ wind farm, New Zealand
The Effects on People near the ‘Te Rere Hau’ Wind Farm, New Zealand
Real-world noise compliance problem at a wind farm
The Effects on People near the proposed Turitea Wind Farm, New Zealand
PART VII - INDIVIDUALS’ PERCEPTION OF WIND FARM SOUNDS
Introduction
The Manawatu – Brisbane Pilot Study
A Study of Noise Sensitivity vs. Specific Sounds
Noise Annoyance
Makara and Waubra studies into adverse health effects
Community perception and acceptance of wind farms
PART VIII - ANNOYANCE, AUDIBILITY, LOW AND INFRASOUND PERCEPTION
Amenity and costs imposed by rural wind farms
Sound Perception
Annoyance
Audibility – Low frequency - Infrasound
PART IX - LOW FREQUENCY NOISE AND ITS EFFECTS
PART X - MEASUREMENT SYSTEMS
Character of sound
PART XI - NOISE MANAGEMENT
PART XII - GLOSSARY
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