Publications and Papers

Presentations at Internoise 2016

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 LAeq,T is often applied to assessments of environmental and occupational noise. LAeq,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.

Technical Notes on Noise - 2015

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:

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) or admin(at)

International Meeting on Wind Turbine Noise - Glasgow 2015

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.


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.

Presentation at Internoise 2014

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.

Presentation given at the 5th International Conference on Wind Turbine Noise Denver 28-30 August 2013

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


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.

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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.

Papers regarding wind farm noise released by MAS Environmental - 2011

MAS Study of article method versus ETSU-R-97

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The effect of a common wind shear adjustment methodology on the assessment of wind farms when applying ETSU-R-97

Summary to: MAS Study of article method versus ETSU-R-97

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A short summary of the above study.


Mike Stigwood
& Terri Stigwood

01223 441671
or 01223 510430

14 South Road,
Cambs, CB24 9PB

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