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How to update the current (failing) noise risk management process to make it much more effective – and self-financing
Noise Induced Hearing Loss claims of £400,000,000 per annum show that thousands of people are suffering hearing damage, most of which could be avoided by changing the way risk management is is carried out.
A simple, innovative approach that dramatically improves the effectiveness of noise risk management was described at the BOHS OH2017 conference in Harrowgate by our technical director, Peter Wilson. The key elements are:-
- current risk management processes are demonstrably not working
- applying simple best practice re PPE and noise control would reduce risks by c 90%.
Make this happen by:-
- making this best practice instantly available to anyone on the shop floor (no noise expertise required) so that it gets used
- use a real-world performance algorithm to evaluate and improve actual PPE performance
- track performance and provide feedback
- taking advantage of the fact that this approach is self-financing – it saves money and time compared with current practice
Click the link below to acquire a copy of the presentation.
You can learn more about the new best practice approach and how to apply it within your own organisation on the one day Noise Risk Management Master Class workshop (Jume 15th, Slough). This also functions as an update to noise competency training and includes the revised HSE draft guidance and the radical new otoacoustic emission hearing damage screening test technology that allows you to track annual changes in the hearing damage of personnel.
The current noise risk management process has failed. This is how we fix it to reduce risk by c 90%…
Noise Induced Hearing Loss (NIHL) claims currently running at about £400,000,000 per annum is unsustainable and demonstrates that current risk management processes have been ineffective and must be changed. Thousands of people are suffering hearing damage needlessly due to a lack of knowledge. Did you know that:-
- PPE – muffs: lose 70% of their performance after 1 month; 90% due to glasses etc; 40% of PPE users get zero protection
- PPE – plugs: most not fitted correctly; as low as 3dB attenuation; women get up to 9dB less attenuation than men
- Audiometry: the damage criteria used include frequencies that do not reflect hearing loss; no threshold shift is necessarily detected despite substantial damage and reported symptoms
Noise Master Class – one day workshop
Book your place to find out how to implement a risk management revolution that can reduce hearing damage risk by c 90% and that can dramatically reduce costs
This one day workshop provides details of the key innovative changes in best practice that should be introduced to reduce the risks of future hearing damage by around 90% at a fraction of the cost of the current conventional (top-down) risk assessment processes. The day is suitable for anyone with responsibilities for risk management who needs to keep up to date with the latest developments and expectations or for people who have previously attended accredited noise competency training. It includes:-
- New HSE guidance: puts the emphasis on action, not placebo documentation and processes
- New approach to risk management: brings together all the simple, effective “low hanging fruit” risk reduction elements, making them easily available to non-specialists. This replaces the current typical “top down” process, giving anyone the means and responsibility to reduce risk – at negligible cost. PPE tool: hearing protection database and real world performance algorithm. Noise control tool: database providing instant access to detailed, low cost engineering solutions to common problems
- New OAE hearing screening test: audiometry does not detect the early stages of hearing damage. Otoacoustic Emission (OAE) does. It can assess and track the actual performance of risk reduction programmes, detecting shortcomings before significant damage is done. OAE
is a fast, objective, low cost test by a technician in a quiet office that assesses noise induced damage to the inner ear structures at an early stage, removing the guesswork as to your risk reduction programme performance. The test will be available for demonstration on delegates in conjunction with Rob Shepheard, Consultant Audiologist and a leading expert on the subject in the UK.
- Digital Noise Assessment (DNA) App beta: this will make the new best practice available to anyone, anywhere on smartphone or tablet with automated action reporting and noise measurement.
Misunderstanding Hand Arm Vibration monitoring marketing material can put hands and safety policies at risk. Caveat emptor.
Stop Press: 27/02/17: HSE has just issued new guidance on HAV measurement and management covering similar concerns. These may well change the way you measure and monitor HAV risk – dramatically… A one-day HAV Master Class and competency update workshop covering these topics is now available. Book a place to ensure that you are up to date with best practice – places are limited. Next Master Class: 20th April 2017, Slough
We are regularly asked about new vibration measurement technology, particularly re the latest hand-held, glove or wrist mounted transducers that are presented as the latest assessment improvements. Whilst they may be useful tools, unfortunately some claims have been disingenuous and end users have misunderstood the limitations inherent in the vibration measurement techniques. Where these techniques do not conform to measurement standards, the results cannot be compared with the regulatory action and limit values. If these values are mistakenly used, then operator risks could be seriously underestimated. Put simply, none of these alternative measurement techniques provide values that can be used for a reliable assessment of the levels of vibration to which operators are exposed as per BS5349.
The following is a summary explaining why alternative HAV measurement techniques may not provide correct values. Click below to acquire the definitive white paper guide.
Why is poor vibration measurement technique such a recurring issue?
Correct measurement technique is a regular issue because the British Standard (BS EN ISO 5349-1:2001 2:2002) technique is time consuming. Common problems include:-
- Service providers taking short cuts: e.g. using hand-held transducers because it is quicker, despite that fact it is inaccurate; strapping accelerometers to tool handles with tape etc…
- New instruments and measurement techniques: many end users have been left with the impression that hand, glove and wrist mounted transducers can be used to carry out vibration measurements to BS5349 – they cannot. Some of the wording used in the descriptions of some systems and services has caused confusion.
Note the statistics used to estimate the relationship between the level and duration of vibration (dose) and the damage risk were based on values from transducers hard-mounted to tool handles. If a new measurement method gives a different value, it is incorrect by definition. Moreover, the HSE guidance recommends spending a minimum on measurement, investing in risk reduction instead. In keeping with this recommendation, for example, most of our HAV risk assessments are taken from our extensive HAV-Base database of accurate field vibration values. This can dramatically reduce (or even eliminate) measurement via virtual assessments by email (contact us for details).
Why non-standard vibration measurement techniques are not accurate
The reasons why alternative measurement systems do not provide vibration values comparable with the regulations are down to the simple dynamics discussed below.
BSEN ISO5349-1:2001/2:2002 measurements: the standard measurement where the transducer is hard mounted to the handle. This can be modeled by a stiff spring with low damping which does not vary. This provides the most reliable and repeatable data which can be compared directly with the regulatory action and limit values.
Hand-held or glove mounted transducer: the transducer is gripped between hand and handle or is mounted in a glove as illustrated. This introduces a set of soft, variable springs with high damping between the handle and the accelerometer. Consequently, higher frequencies are progressively filtered out. In addition, the handle shape and grip strength can seriously affect the measured level of vibration (for a constant vibration source). It is not difficult to measure levels that are less than half the correct value.
Wrist mounted transducer: wrist mounted “watch” based transducer are very effectively vibration isolated from the source. Only low frequency vibration is transmitted into the accelerometer. Consequently, the measured value can bear even less relationship to the actual vibration in the handle than for hand-held transducers. It is also highly variable – how tight do you wear your watch-strap?
HAV tool vibration measurement – the hard (and only correct) way…
The BS5349 measurement technique minimises the number of variables involved in hand-arm vibration measurements and provides the only accurate levels that can be compared with the risk statistics (the basis for the action values in the regulations). That is not to say it is not possible to devise better measurement techniques, but many years of work would be required to relate any vibration values to operator risk.
Some marketing literature surrounding the use of hand-held, glove or wrist mounted transducer measurement systems can be misleading if it gives the impression that the vibration values can be used directly in operator risk calculations. If incorrectly used in this way, these values can dramatically underestimate the risks to operators which could lead to avoidable heath issues and potentially serious repercussions should there be a claim.
If you need to carry out full HAV risk assessments (as well as measurements), there is a best practice guide checklist and open source template tool register available for download. We can also provide a full range of HAV training courses and workshops (up to full competency).
The availability of this new test will have a dramatic effect on the management of hearing loss prevention programmes…
New technology has become available that provides companies with data that they can use to check the real world performance of their hearing conservation programmes very quickly and very easily. It is a development of otoacoustic emission (OAE) screening technology that, unlike conventional audiometry, can be used to detect the very early stages of damage to the outer hair cells in the cochlea. Coupled with the latest hardware, it is a fast, objective, accurate and low cost test that can be used to assess the difference between the theoretical and the actual protection afforded by PPE programmes.
Applying OAE in practice
OAE has been used as standard practice to evaluate the hearing of babies for many years, but is relatively new in the industrial arena. However, AkzoNobel in the Netherlands, for example, has been using OAE to track changes in the condition of staff hearing to inform risk management procedures and as a motivational tool. OAE is an objective test that does not require special soundproof facilities (a quiet office will do) and the results, (in the form of % damage) are easily understood and tracked. An HSE report on the usefulness of OAE testing in occupational health surveillance (in 2011) concluded, that, even then, it was useful for the early detection of at risk groups and commented on the value that it can bring to preventative risk management of noise health risks.
Noise competency training update
As OAE will become an important element of best practice, we will soon be updating our IOSH competency training courses to reflect this fact. These one-day refresher Master Classes will be run in conjunction with Rob Shepheard, Consultant Audiologist and a leading expert on the subject in the UK. Contact us if you’d like advanced information on the dates and venues.
Would you like to test the technology on your site at no cost?
Rob would like to run some additional field trials of the technology as part of a fully funded project (via Acton Plan on Hearing Loss – NHS). This would involve testing a small number of noise exposed personnel and collating the results – at no cost to the host company. You would get the results and be able to test the approach in advance of its imminent adoption as part of best practice.
Please contact us if you would like to discuss the changes we foresee in best practice and the potential benefits to your company. If you would like to take part in the study, contact us or contact Rob directly at firstname.lastname@example.org +44-1603-208419.
This is one of a number of highly rated, interactive and practical noise related workshops developed for Environmental Health Officers. They are held locally by a host authority, saving on travel, time – and at a fraction of the cost of conventional training. It can even be a profitable exercise…
Noise Workshop Content and Objectives
Make the best use of your equipment and speed-up the processing of recordings
Northampton Borough Council: Thursday 27th October
The ability to record sound files is increasingly common – noise nuisance recorders, sound level meters or smartphones. This workshop covers the practical techniques that make recording and subsequent analysis much faster and more efficient, including procedures for accurate and reliable calibrated recording using complainant operated noise nuisance or any other type of recorder. It also covers subjective and objective analysis of recordings (particularly on PCs) and the use of frequency analysis related both to BS4142 and to noise source diagnosis.
The workshop is an opportunity to acquire practical techniques, short cuts and “tricks-of-the-trade” that reduce dramatically the time required to solve intractable noise problems. The workshop carries 2 CPD points and includes:-
- Noise Recording Best Practice
Sound level meters and noise nuisance recorders – complainant issues – £100 on the web converts any old SLM into a sound recording meter, or use a smartphone…
- Best Practice in Processing Recordings
Techniques that speed-up both subjective and objective analysis, from ears to PCs
- Interpretation and Source Diagnosis
Is it a fan – or a pump? Does it exist? Low frequency issues…
- Remote Control of Noise
Free evaluation of what constitutes BPM with costs typically 80% lower than conventional mitigation
- Free audio playback analysis software
Contact us to book a place or to run your own workshop locally.
A simple way to cope with mobile plant and tools
A question about a common problem that came up when giving a presentation at a recent IOSH meeting has a really simple answer. What struck me was the enthusiasm for a solution that we developed and been advocating as best practice for years in our training courses. Whilst the talk was on noise and noise control, the approach is equally applicable to Hand-Arm Vibration – in fact, combining the two (where appropriate) saves resources.
Q: “How do you assess noise risks from mobile plant in practice when tools and locations change all the time?”
A: “Put labels on the plant showing the distance within which PPE is mandatory.”
The very mobility and variations in the tools or mobile plant in factories or on construction sites, at first glance would seem to make it difficult to manage and police likely exposures. For noise, the risks for a “quiet” operator may suddenly escalate when a jack hammer starts up nearby. For HAVS, the degree of risk from a particular tool use may not be obvious (unless you can do the calculation in your head).
Combining Noise and HAV Data
We advocate creating a spreadsheet database of the items of plant which lists noise levels at the ear and also calculates the “safe” working distance within which PPE
is mandatory i.e. the distance at which the noise falls to below 85dB(A). This figure should be calculated for the worst case i.e. when there are reflecting surfaces nearby (which can increase the local noise level by several dB). The same spreadsheet should also include the levels of vibration (where appropriate) and the calculated “safe” working time to reach the Exposure Limit Value (ELV) of 5m^2 (single tool use finger-on-trigger time). Our free template HAV spreadsheet is available via this page.
Print labels for the plant and tools. To check risk management on site, you don’t need a sound level meter or a HAV exposure calculator, you just look at the stickers. A glance at a tool label not only tells you how risky the noise is (it also informs the operator – very simply and with no noise knowledge required), but also who should be wearing PPE. The HAVS version is a very simple way to inform about relative risk (albeit, for single tool use) and is the basis for questions for operators about how long they have been using the tools.
Not perfect, but very simple and very effective…
We already have a huge database of both noise and HAV data for mobile plant and tools that we use to implement this approach. Instant virtual noise and HAV assessment by email…
I’d like more information or to discuss the practicalities
INVC recognised at the UK Energy Innovation Awards
This annual event is organised by the Energy Innovation Centre to celebrate the most successful innovations arising from collaborations between SMEs and the energy networks. In our case, we were awarded the “Environmental Impact Award” for our work in collaboration with Echo Barrier to develop innovative new ways to minimise the noise impact of gas pipe replacement work in built-up areas.
High levels of noise from the equipment used (breakers, saws etc) to dig holes and trenches in roads is a perennial problem, both to pedestrians and to local residents who often overlook the work. There are also the practical problems associated with working in confined areas (increased noise due to multiple sound reflections) with mobile plant that has to be moved quickly and easily with a minimum of staff.
The solution was to develop custom versions of the acoustic tent (with wheels) plus additional mobile acoustic screens making use of the advanced Echo Barrier technology. This means that high noise attenuation can be achieved using low weight components (including a patented waterproof acoustic absorbent layer) which aids with the high degree of mobility and practicality required for this type of project. The typical noise reductions from the INVC designed system are 13dB – 18dB in very confined built-up areas, rising to around 20dB – 25dB when used in the open.
The award is recognition, of our ability to blend practical experience (in this case in construction, demolition and infrastructure noise projects) with innovative engineering to generate new best practice in noise control.
Learn how to cut fan noise attenuation project costs by 50% – 110%*
Fans are the most common of all occupational and environmental noise sources (NPL figures suggest that two thirds of complaints about noise from industrial premises are related to fans). However, most typical fan noise control projects still only consider high cost antediluvian palliative techniques that haven’t changed since Victorian times. Conventionally, the only techniques used are:-
- silencers / attenuators (can reduce efficiency)
- enclosures (reduced access, heat build-up)
- lagging (corrosion problems)
- barriers (very often ineffective)
- building modifications (seriously expensive)
However, there is a host of alternative techniques that should be considered before falling back on these palliatives. These include:-
- Aerodynamic modification technology
typically 10% – 20% of the cost, increased efficiency
- Chiller / HVAC innovative noise control techniques
<20% of the cost, free cooling unaffected, higher efficiency
- Fan / stack systems
bespoke retro-fit attenuation, low cost, fast, more efficient
- Burner / combustion noise
source control technology – typically <5% of the cost
- Acoustic Camouflage
psychological silencing to hide nuisance noise
The Fan Noise Control Master Class is designed to address this failing. It provides a definitive guide to all the fan noise attenuation options that are available with current technology. Delegates find out how to assess what constitutes “best practice” in assessing and controlling the noise from any type of fan, from take-away kitchen units to massive industrial fans. It also includes practical advice on the best measurement and analysis techniques and on the specification of noise limits. You also gain access to a free advice service to give you a second opinion to avoid potentially expensive mistakes…
“..the best lecturer I have ever had with relevant case studies.” Jon Tofts: PPC officer Environment Agency
Topics covered include:-
- Fan noise reduction options
Instant, low cost, retro-fit attenuation techniques for many common fan noise problems; material specifications; installation geometries; conventional silencer types; setting fan noise specifications; review of innovative aerodynamic source control and improved efficiency technology (silencing without attenuators). Many innovative noise control projects can improve system efficiency, making them self-financing
- Diagnostic techniques – smartphone recording and analysis
Problems with BS4142; BAT / BPM evaluation techniques; convert old sound level meters to calibrated sound recorders for £100; fan noise analysis – from ears to computers…
- Remote control of noise – speeds up projects and complaint resolution
The information needed to get a free evaluation of the fan noise control options and costs by email (smartphone recordings and photos)
Free FrequencyMaster noise analysis software (usually £900)
All delegates are provided with a free personal copy of our FrequencyMaster Noise Analysis Software. This provides easy to use access to 1/1 – 1/3 octave and tonal noise analyses from recorded data. We use this software ourselves on a daily basis to evaluate and diagnose fan noise problems.
*where increased system efficiency saves power or increases productivity
International Occupational Hygiene Association (IOHA) Conference Paper: 27th April 2015
Peter Wilson: INVC Technical Director
HSE Research – PPE is generally ineffective…
HSE research proving that hearing protection is not effective across most industrial applications (our summary of the PPE research is available here) provides a gold plated opportunity for the legal profession to drive a coach and horses through hearing damage claim defences based on PPE use. Consequently, as real-world PPE performance is so compromised, the best way to guarantee low levels of risk at low cost is to reduce the noise levels. This workshop paper demonstrates how occupational health and other professionals can add value to noise risk assessments by linking to best practice in engineering noise control to reduce the risks of hearing damage dramatically.
How to Add Quiet to Noise Assessments
Whilst noise control is not always practical, occupational health specialists are generally unaware of the technology that is now available. This can not only reduce hearing damage risk at a fraction of the cost of conventional measures, but, oxymoronically, it is self-financing surprisingly often as it reduces the requirement for PPE and can actually improve plant operation and productivity.
The paper provides a detailed guide as to how to modify the noise risk assessment process so that professionals without engineering expertise can generate the information required for a preliminary evaluation of the noise control options, costs and benefits. It also provides supporting material in the form of a host of multimedia case studies.
The Conference Paper Presentation
The International Occupational Hygiene Association (IOHA) 2015 Conference was organised by the British Occupational Hygiene Society (BOHS). See http://www.ioha2015.org/agenda-day-1/ for more information. The presentation? “I attended your noise control workshop and had a great time, I found it both engaging and thought provoking.” Trevor Laurent: Air Surveys Ltd.
We also have a White Paper version of this presentation with more detailed content. I’d like a copy of the IOHA White Paper please >
A brief guide on how to evaluate low frequency noise problems quickly and without spending any money.
Evaluating low frequency noise complaints is one of the most common (“bane of my life”) issues that EHOs contact us about. Using the right approach, we can sort most of them within a few days. The following is a brief, practical guide detailing solutions to the most oft encountered initial evaluation problems using a tool that won’t cost you a penny.
Case Study: Low Frequency Extract System Noise Evaluation
This fan extract system was the cause of numerous complaints about a very low frequency hum / woofle / throb. Frequency analysis of audio recordings showed the problem to be a 35Hz tone plus first harmonic. As this did not tie-in with fan speeds etc, we immediately knew that it must be a resonance. One site visit later and the problem was resolved by altering the duct acoustics and inserting an aerodynamic flow control plate to improve the system efficiency. The tones were eliminated and the broadband noise was also substantially reduced at a cost <£1k.
An entirely zero cost way to analyse this type of problem is detailed below.
Low Frequency Noise Complaint Evaluation
Forget dB(A), it is irrelevant as it filters out low frequency sound (-39dB at 31Hz). If I had a £ for every extensive set of logged dB(A) plots carried out as part of a low frequency noise evaluation…
The best option. Record samples with plenty of gain for subsequent listening and analysis. Ideally, we like to get 2 or 3 recordings when the noise is bad and a further couple when it is not there or less prominent. That’s it: no prolonged sets of logged data.
I can’t hear anything on play-back
The problem with very low frequency sound is that you need speakers the size of a wardrobe or an unusually good set of headphones. The best results in practice can often be obtained with a good set of in-ear buds that are well screwed into your ears. However, you can use our free QuickRecord software utility to play-back at a higher speed. We would usually use a x3 or x5 speed increase to shift a hum at perhaps 40Hz up to 120Hz or above where you can clearly hear hums etc. whilst using kit that ordinary mortals can afford… Install the utility, open a wav file and hit play. Pause, click the button next to play and select your preferred speed, un-pause to listen further. Email or call us if you’d like a copy of QuickRecord – email@example.com. Note: QuickRecord usually runs fine in Windows 7, but it is supplied “as-is” with no support.
Alternatively, you can download the open source Audacity software which allows you to achieve something similar.
Here, after loading the sound file into Audacity, I’ve selected “Effects” and “Change Speed”, and a 200% increase which will double the frequency on playback (the file duration displayed is halved to match). Don’t save the file!
You can use the spectrum capability in Audacity to take a quick look for any tones. Revert back to 100% speed and then select a section of the wav file time trace (left click and drag). Then select the “Analyze” tab and “Plot Spectrum” from the drop-down list of options. This displays a simple spectrum. Note that the log X axis allows you to view the low frequency end of the signature more easily, but you lose the ability to spot harmonics by eye (they are evenly spaced on a linear X axis). In this case, the dominant 35Hz tone can clearly be seen.
…and back to the reality of the case study
Contact us if you need help with analysis of a specific problem or the interpretation of results. The most common causes of low frequency noise problems are fans, chillers, burners, compressors etc. We have developed low cost, elegant engineering noise control measures for all of these sources – see this wide range of environmental noise control case studies.