Annual report 2000-2001

Manager's Statement

ISVR Consultancy Services is a self-funding advisory unit which carries out short- and medium-term consultancy and applied research projects for a wide range of clients in the public and private sectors.  The unit operates on a commercial basis, with full-time engineering and support staff, and is a Founder Member of the Association of Noise Consultants (ANC).  The Unit maintains close links with the ISVR Research Groups, and a number of projects are undertaken in collaboration with academic and research staff.  The Unit website is at www.isvr.co.uk.

There have been a number of staff changes in the reporting period.  Mr Dave Rawlinson has returned to the fold after 16 years outside the ISVR.  Mr Neil Pinder has retired after 29 years with the Unit.  The former manager, Dr Andrew Bullmore has moved on to another acoustic consultancy, and Mrs Hilary Smith, the Unit Secretary, who also acted as secretary to the Editor of the Annual Report, has moved to a new post in the Engineering Enterprise Office within the university.  Their contributions to ISVR Consultancy Services are much appreciated.

Mr Stuart Dyne, formerly head of the ISVR Shock Analysis Laboratory, has been appointed to the post of Manager. 

Summary of Activities

Consultancy projects are client-confidential.  However, the following outline descriptions of projects in progress during 2000-2001 illustrate the range of work undertaken and the general direction of consultancy activities.  During the period there were nearly 350 enquiries logged, with over 35% becoming actual projects.

Environmental Noise

There has been a continued growth in demand for environmental noise assessment studies in connection with new developments or in cases of alleged noise nuisance.  In many cases, these projects lead to an appearance in Court or at Public Inquiry. 

Projects included the assessment of noise likely to result from increased activity at a military firing range in Cumbria and from various commercial and industrial developments including supermarkets and mineral extraction sites including, in some cases, assessment of the impact of noise on wildlife as well as people.  A major project concerning a proposed container terminal on Southampton Water is in progress. 

Extensive surveys were carried out along the route of a new motorway in the Midlands to establish pre-scheme noise levels.  These measurements were also used to evaluate and validate a range of recently-available noise mapping software.  An EU Directive will require local authorities responsible for major conurbations to produce and maintain noise maps to serve as benchmarks for planning purposes.  This development is likely to offer significant business opportunities to software companies and consultants.  However, further work is required to define the virtues and limitations of noise mapping, and to develop guidance on how noise maps can be used within the planning process. 

A number of studies have concerned the assessment of the suitability for residential development of sites which are exposed to noise or vibration from transport or industry.  Noise levels are generally assessed using standards set out in Planning Policy Guidance document PPG 24.

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Litigation Work

In addition to the public inquiry activity referred to above, a number of investigations have been carried out to prepare evidence in connection with criminal cases, where questions were raised about the ability of witnesses to hear or recognise specific sounds.  One of these concerned a widely-publicised murder investigation.  In many other cases the unit has undertaken analysis of recordings made during alleged criminal activity, often with the aim of enhancing the audibility of recorded events or speech, and frequently involving transcription work.  Several unit staff attended an expert witness training course as the volume of work in this demanding role has increased.

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Noise and Vibration Control Engineering

As usual, there has been a significant number of diverse projects involving the practical application of noise and vibration control techniques to industrial processes and machinery and to consumer appliances.  The list includes a number of marine projects ranging from the noise control design for a new high-speed gas turbine-powered luxury motor yacht to a vibration problem on an undersea oil production system.  Other areas of activity include calculations of low frequency noise from a diesel power station stack, ground-borne noise from water pumping stations and estimates of shock noise from a fuel testing rig.

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Structural Dynamics and Computational Acoustics

This category has also seen a wide range of studies, with a significant number concerning the useful effects of sound and vibration.  Prominent amongst these have been some very palatable projects for the food industry: a study of the effect of vibration on the flow properties of liquid chocolate and some specialised acoustical problems for vending machine manufacturers.  Other projects involving the useful application of sound and vibration have been follow-on mathematical modelling studies for the manufacturer of a mass-flow meter and the manufacturer a fluid flow meter.

In other areas of computational acoustics there has been continued activity on existing long term projects including duct acoustics modelling under the auspices of the Rolls Royce UTC, the modelling of aerodynamic noise generation from aircraft under the EU-funded RAIN project, and the modelling of noise and vibration transmission problems using Statistical Energy Analysis (SEA).  The SEA activity, deriving mainly from sales and consultancy associated with the AutoSEA package, has been particularly profitable this year.  A substantial number of projects have involved the application of modal analysis methods, including a particularly intensive experimental program for a UK-based manufacturer aimed at understanding vibration problems in a circuit board printing machine.

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Test and Experimental Work

ISVR Consultancy Services operates and manages the main the ISVR test chambers, including the large anechoic chamber, which is increasingly used for product testing as well as for undergraduate and postgraduate research. 

High intensity testing of aerospace components continues to be a major element of testing work.  The progressive wave tunnel facility, located in the P E Doak Aeroacoustics Laboratory, has been refurbished to reduce the transfer of noise to other rooms in the building so as to permit unrestricted operation at high sound pressure levels.  The facility has been used for major test programmes for composite aircraft fuselage components at SPLs of around 165 dB.

Laboratory tests to determine sound power levels have been performed on equipment such as shipboard machinery, computer peripherals, air-conditioning units, cellular telephone base stations and domestic 'white goods', using reverberant and hemi-anechoic test methods.  An increasingly large part of the Unit's testing is now associated with development work to reduce the noise levels of a variety of products.  One project has concerned the development of a novel type of attenuated ventilator unit for use in housing or hotels affected by high levels of external noise. 

There is an increasing demand for testing of airborne and impact sound insulation between dwellings.  It is clear that the minimum insulation standards required by the current Building Regulations (for England and Wales), as set out in Document E of the Regulations, do not satisfy the expectations of many people moving into new homes.  The government agency responsible has published proposals for new Regulations as a Consultation Draft, although there is a general view (not necessarily shared by builders and developers) that the proposed changes are not adequate to provide the considerable improvement in sound insulation standards which is clearly required.

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Noise at Work, Communications, Hearing Conservation and Personal Injury Claims

The Unit has wide expertise in the assessment of speech intelligibility, audibility of warning signals, and in the design and development of electroacoustic systems.  A wide range of projects in this field was completed or started during the year. 

A number of assessments of workplace noise have been completed, to meet the requirements of The Noise at Work Regulations 1989 and to assist employers in developing hearing conservation policies and procedures.  These have included, for example, a food processing factory, bar staff in a London club, a credit card manufacturer, and print rooms, including one on a cruise ship.  One particular survey was carried out just before Christmas in a turkey processing plant: the ISVR Consultant suffered a slight loss of appetite over the festive season! Peak noise levels from small arms, handguns and pyrotechnic devices were measured at the training establishment of a large city police force.  The results were assessed in relation to the Action Levels of the Noise at Work Regulations; a number of firearms instructors were making compensation claims against the force for hearing injury leading to premature retirement.  In a related job, hearing protector attenuation was determined for a sample of earmuffs used by police instructors and officers undergoing firearms training. 

The Unit is regularly instructed by solicitors in connection with employee claims for noise-induced hearing loss.  Most of these claims relate to alleged long-term exposure to noise in manufacturing industries, although many relate to noise from communications or test signals through headsets.  These require specialised measurement methods using an acoustic manikin or miniature microphones.  In one example, the noise level of a fire alarm system was assessed in a hospital in respect of a hearing injury claim by a fire-fighter.  The officer was observing a simulated evacuation of patients form a ward and suffered tinnitus after a considerable time spent close to the alarm sounders. 

Measurements were carried out for several police services.  These measurements were of noise levels and exposures from the headsets used by control room and switchboard operators, covert and overt earpieces used with personal radios, earpieces in motorcycle helmets, and headsets used by staff transcribing recorded interviews.  In each case a manikin was used to compare noise exposures with the Action Levels of the Noise at Work Regulations to verify compliance.  Similar measurements of headset output were carried out for the control room of a fire and rescue service and in a number of call centres for building societies, an insurance company and a directory service.   

Further noise measurements for a fire and rescue service included various items of equipment used by fire-fighters including pumps, an aerial ladder platform, positive pressure ventilation fans, generators and compressors, radios, distress signal units.  Noise within vehicles on the road, with and without sirens, was also measured.  This work, and the control room measurements described above, formed part of a comprehensive safety audit carried out by the Hampshire Fire and Rescue Service, and our reports are available on their website for the benefit of other brigades. 

A medical equipment manufacturer commissioned a worldwide review of current workplace noise exposure regulations, and of likely future changes which might arise.  It is clear that there is pressure to introduce lower exposure limits in the light of recent discussions concerning the EU Physical Agents (Noise) Directive and a report sponsored by the World Health Organization. 

  

Man the pumps: fluid pumps in industrial sites, water pumping stations and on boats frequently cause noise problems through structure-borne and water-borne noise transmission

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Publications

Bullmore A.J., Noise: Planning Issues and Legislation, Proceedings of the Institute of Mechanical Engineers Conference on Noise Legislation, London, 1999

Bullmore A.J., Meteorological effects on outdoor noise propagation over large distances, Proceedings of the Institute of Physics Conference on Environmental Noise, London, 1999

Smith, M.G. and *Lewis, D.N., Noise reduction in a cyclone separation system - A Case Study, Institute of Acoustics Industrial Noise Group, Stratford-upon-Avon, November 2000, 22(5), 87-94

* Not working in ISVR

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Archive of our Annual Reports from other years
 

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