Publications and Papers

Download PDFs of the papers presented at Internoise 2017 in Hong Kong.

Diminishing reliability of the application of Standards on Environmental Noise in the UK - Mike Stigwood

Abstract: This paper is one of a series reviewing the development and application of guidance and standards on environmental noise in the UK. The first paper in this series, presented at Internoise 2016 looked at evolving problems with British Standard 4142 for industrial and commercial sound due to introduced ambiguity and a diverse range of problems. This paper reviews the practical application of standards.

Community noise is generally divided into sources of environmental (transport), neighbour and neighbourhood noise (arising from commercial sites) with different principles applicable to each many without any decibel guidance. Boundaries between the assessment and determination of these three types of noise sources and determination of their acceptability are increasingly blurred in the UK with practitioners arguing guidance for one as directly transferable to others. Confusion and ambiguity regarding the interpretation of standards is arguably beneficial to developers and noise producers who may emit excess noise and those wishing to develop land in noisy areas. An inherent inability to enforce noise controls arises as any interpretation of compliance with standards is duty bound to apply the least onerous interpretation as in the UK it is normally subject to a criminal standard of proof. One of the most commonly applied standards in the UK is BS4142: 2014. Its revisions have introduced widespread ambiguity, uncertainty and contradictory application which were reviewed at Internoise 2016. In this study I examine, at random, a wide range of noise impact assessments provided within the UK applying guidance. I compare how that guidance is interpreted, whether limitations are correctly applied and the application in general of decibel based guidelines outside its scope. The findings identify widespread misuse of standards, the lack of adequate review of assessments and significant inconsistency in guidance application.

Keywords: Standards, Noise Surveys, Perception, psycho-acoustical factors.

Mike's presentation which contains suggestions on how to deal with the problems he addressed can be viewed here.

Preliminary evaluation of the relative importance of acoustic, non acoustic and context related factors in reactions to noise at the individual level - Daniel Baker

Abstract: The reaction of an individual to a particular source of sound varies. This is dependant upon a number of acoustic, non acoustic and context related factors. This preliminary study considers the impact of noise arising from three sources of neighbourhood noise affecting people living in residential dwellings in the UK.
The sources of neighbourhood noise include a blanking press, chiller units and drop hammers. In each case the noise was considered intrusive and at a sufficient level of interference, at the individual level, to result in complaints. This paper evaluates a number of acoustic, non acoustic and context related factors and how these rank, relative to the importance of those factors, in affecting noise reaction in each case. The preliminary findings demonstrate residents who were sufficiently annoyed to complain considered non acoustic and context related factors equally as important as acoustic factors. It would appear a greater emphasis on non acoustic and context related factors is necessary when assessing the likely negative reaction or affectedness arising from exposure to specific sources of neighbourhood noise. It is considered necessary to develop an internationally recognized questionnaire for assessing the impact of specific sources of neighbourhood noise.

Keywords: Annoyance, neighbourhood noise, non acoustic factors, context

Topics: T7.1 Community noise & ratings, T10.0 General (Noise & health)

Cotton Farm Wind Farm long term community noise monitoring 4 years on: testing compliance and AM control methods - Sarah Large

Abstract: The Cotton Farm Wind Farm in East Anglia, UK, has been operating for approximately 4 years. There have been significant and widespread community complaints. Despite compliance testing by the operators and assessment of nuisance by the local authority, significant complaints continue without any resolution. A lack of clear guidance on how to assess AM is the reasoning of the local authority for failure to act and the operator's compliance testing has shown that the wind farm can, in a reduced operational mode, meet its limits. In 2013 MAS Environmental established a permanent monitoring station to record and publish data online, located 600m from the nearest turbine. This allows correlation of impact upon the community and establishes a library of wind farm noise data. This paper reviews the long lasting impacts of the wind farm and using data from the community monitoring station investigates how a 'compliant' wind farm continues to cause significant disturbance. The averaging processes used by many when assessing compliance with ETSU-R-97 are examined in relation to specific complaints and the new UK Institute of Acoustics and WSP / Parsons Brinckerhoff methodology for quantifying and assessing AM is tested. Using real world data from a site where there are continuing complaints, this paper assess whether current methodologies for assessing noise impact are fit for purpose.

Keywords: Wind Farm Noise, Amplitude Modulation, Compliance Monitoring

Download PDFs of the papers presented at Internoise 2016 in Hamburg, Germany.

Diminishing reliability of standards on environmental noise - Mike Stigwood

Abstract: Revisions to British Standards in 2014 introduced significant changes in guidance on noise with complex and unexplained limitations. This results in multiple interpretations, assessment methodologies and outcomes depending on the approach applied. Community noise is generally divided into sources of environmental (transport), neighbour and neighbourhood noise (typically arising from commercial sites). The boundaries between different sources is increasingly blurred in the UK with practitioners arguing guidance for one is directly transferable to others. Confusion and ambiguity regarding the interpretation of standards appears beneficial to developers and noise producers who may emit excess noise and those wishing to develop land in noisy areas of the UK that might otherwise be refused permission. An inherent inability to enforce noise controls arises as any interpretation of compliance with standards is duty bound to apply the least onerous interpretation as it is subject to a criminal standard of proof. This problem is compounded with interpretation of controls by UK courts permitting contradictory outcomes and different meanings.

Widespread ambiguity, uncertainty and contradictory interpretations now introduced are demonstrated using practical examples. Nullification of existing controls protecting communities in the UK and future guideline principles are explored.

Keywords: Criteria, rating, industrial

Relevance of the equal energy principle to individual sources of neighbourhood noise - Daniel Baker

Abstract: The characterization of noise is relevant to acoustic disciplines concerned with effects and impact on humans. The L_Aeq,T is often applied to assessments of environmental and occupational noise. L_Aeq,T is used as an environmental noise descriptor for characterizing the total ambient sound environment and specific elements of the soundscape. Environmental noise standards generally concentrate on dose response relationships based primarily on research of transportation sources. However, such relationships do not appear to exist for specific sources in the sound environment, for example neighbourhood noise arising from a specific site, due to non-acoustic factors. This paper considers three sources of neighbourhood noise that are discriminable at residential dwellings. Reliance on the equal energy hypothesis, applied to neighbourhood sources, appears to understate the impact of noise on receptors following repeat exposure when applied to specific elements of the soundscape. Application of the equal energy principle as a means to characterize noise impact and its effects appears less relevant to the specific sources considered. Standards for characterizing sources of neighbourhood noise are required to provide a complete assessment considering not only the total ambient noise dose but specific components of the sound environment and annoyance response.

A quantitative and qualitative review of amplitude modulation noise from wind energy development - Sarah Large

Abstract: 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.

Application of noise guidance to the assessment of industrial noise with character on residential dwellings in the UK - Daniel Baker

MAS have published a technical note in the Journal of Applied Acoustics entitled "Application of noise guidance to the assessment of industrial noise with character on residential dwellings in the UK"

The article is available via the Elsevier website online and as a free pdf download until 5th April 2015. After this date there is a charge to access the publication.

The article may be accessed via the link below:

http://www.sciencedirect.com/science/article/pii/S0003682X15000298?np=y

The technical note conducts a critical review of noise guidance routinely used to determine the acoustic acceptability of site identifiable industrial noise on new or existing dwellings. This includes the WHO Guidelines for Community Noise 1999, WHO Night noise guidelines for Europe 2009, BS8233 2014 Guidance on sound insulation and noise reduction for buildings and BS4142 2014 Methods for rating industrial sound affecting mixed. The technical note compares four sources of industrial noise with character including a supermarket delivery, blanking press, metals recycling and metal fabrication.

The technical note should be of interest to professionals working in Environmental Health and Acoustics who regularly use noise guidance to assess proposed residential or industrial developments or existing industrial noise impact on dwellings.

Audio is available for the graphs presented within the technical note which should assist understanding.

We are interested in receiving feedback on the article particularly from Environmental Health Professionals. Any questions can be sent to dbaker(at)masenv.co.uk or admin(at)masenv.co.uk

Download the paper presented at the Sixth International Meeting on Wind Turbine Noise Glasgow, Scotland, 20th – 23rd April 2015

Cotton Farm Wind Farm – Long term community noise monitoring project – 2 years on.

Abstract

In 2013 MAS Environmental established a permanent monitoring station to record and
publish data online, located 600m from the nearest turbine, to correlate the impact upon the community and provide an extensive database. This database enables a wider study of the effect of a number of variables in the noise immission on the communities affected. The database has enabled testing of proposed controls, particularly in relation to audible amplitude modulation. Previous papers in 2014 on this project have described its background and the early results of the data collected,
especially in relation to the occurrence of the special characteristic amplitude modulation.

This paper includes further evaluation of the now extensive database collected over nearly 2 years and how noise features correlate with community response / complaints, including analysis of some of the prominent characteristics recognized as a feature of the community noise as created by this wind farm and how they impact. The data has also been used to test the appropriateness and reliability both of some commonly applied and also emerging principles and methods for Amplitude Modulation (AM) noise control used for wind farms. It identifies issues relating to uncertainty, error and reliability / repeatability. In this paper particular focus is placed on the analysis of automated or semi-automated Fast Fourier Transform procedures and whether they can adequately detect and quantify AM. This part of the long term study focuses on the parameters and procedures used to identify AM noise.

Analysis of the inability of noise controls to reflect true impact in relation to Cotton Farm wind Farm data is also explored.

Download PDFs of the papers presented at Internoise 2014 in Melbourne, Australia.

The noise characteristics of 'compliant' wind farms that adversely affect its neighbours - Sarah Large, Mike Stigwood

Abstract: In the UK many wind farms cause complaints of noise despite complying with control limits. Problems relate to reliance on the LA90 index, failure to consider or apply ratings on the context of the sound characteristics and actual human responses due to complex characteristics. In general in the UK low frequency and very low frequency sound effects are either ignored or denied. The complex interrelationship of features within this noise and difficulties in quantifying and qualifying noise impact and inappropriate comparison with other sources of noise renders the effects difficult to investigate or quantify with contradictory outcomes possible using the same data sets. Claim and counterclaim of health and adverse effects complicate the analysis. This paper explores some of the interrelating characteristics of wind farm noise measured and observed in the field that appear to influence complaints made by communities. Cumulative effects occurring in environments normally dominated by natural sounds and both audible and inaudible elements remain alien sounds which are not habituated to. It appears that sensitisation arises. The physical reason for the failure to appropriately identify modulating noise effects and in particular low frequency modulating noise problems are explored.

MAS Environmental presented the following paper at the 5th International Conference on Wind Turbine Noise Denver 28-30 August 2013

Audible amplitude modulation - results of field measurements and investigations compared to psychoacoustical assessment and theoretical research

Summary

In the UK the cause of amplitude modulation (AM) and the ability to predict its occurrence is considered abstruse by many. Few have experienced or measured AM and yet conclusions are frequently made asserting that it is rare and that any action to counter its effects is limited by minimal knowledge surrounding its nature and cause. This paper aims to advance current knowledge and opinion of AM. Methods used to successfully investigate AM are confirmed. AM should be measured during evening (after sunset), night time or early morning periods. Meteorological effects, such as atmospheric stability, which lead to downward refraction resulting from changes in the sound speed gradient alter the character and level of AM measured.
AM is generated by all wind turbines including single turbines. Propagation conditions, mostly affected by meteorology, and the occurrence of localised heightened noise zones determine locations that will be affected. Measurements from eleven wind farms have been presented and discussed in relation to current research and theory. Findings confirm that AM occurrence is frequent and can readily be identified in the field by measuring under suitable conditions and using
appropriate equipment and settings. Audible features of AM including frequency content and periodicity vary both within and between wind farms. Noise character can differ considerably within a short time period. The constant change in AM character increases attention and cognitive appraisal and reappraisal, inhibiting acclimatisation to the sound. It is advised that those responsible for approving and enforcing wind energy development improve their understanding of the character and impact of AM. This can be achieved by attending a listening room experience which has been trialled and is discussed in this paper.

Download the paper (pdf)

Download the presentation (pdf)

View the animated graphs (flash)
 

Other useful papers presented:

Assessment of wind turbine noise in immission areas (pdf)
by Hideki Tachibana Chiba Institute of Technology, Hiroo Yano Chiba Institute of Technology, Akinori Fukushima NEWS Environmental Design Inc.