Noise NOT at work #2: How loud is…Historic Motorsport? A weekend at Spa Francorchamps by Johan Beavis-Berry (WBM)

In a world where road traffic noise is near-omnipresent, it might seem hard to believe that anyone could find pleasure in the sound of cars. In fact, motorsport enthusiasts would be delighted to explain the nuances of why a Porsche flat-six engine is without question the greatest sounding engine of all time, for example…

Despite harbouring highly subjective opinions on automotive sonic perfection, car fans will admit that racing events can be loud. Signs like the one below are plastered across UK motorsport venues, yet noise exposure is not always at the forefront of spectators’ minds.

As a conscientious acoustician and musician, I take my hearing seriously. My earplugs are always close at hand, and I’ll use them even in circumstances that wouldn’t raise the eyebrow of a librarian. Needless to say, dozens of unattenuated racing cars passing by at full speed would be unwelcome at a library.

The trip to Spa Francorchamps (in September 2025) began with a seamless drive from Gloucestershire to Folkestone and the Eurotunnel. The 3.5-hour backseat journey by Land Rover Freelander yielded an overall sound level of 74 dB L_Aeq,T with general conversation and no music – so far, so good. To preserve the battery of the dosemeter, no measurements were taken during the European leg of the journey, leaving opportunities for further research comparing British and French road noise. Similarly, typical sound levels in Belgian bars were undocumented on this occasion, with subjective impressions blurred by intoxication.

Friday morning saw us slightly worse for wear and arriving at the circuit by 10:30, with racing already underway. Once coffees had been obtained, we spent some time in the paddock area, where competitors were busy preparing their cars. I optimistically left my earplugs in my pocket but quickly changed my mind after observing levels of up to 110 dB(A) on the dosemeter. Our spectating began on the start/finish straight, with a combined race for pre 1965 and pre 1981 sports cars, though a long safety car period following a crash at La Source hairpin significantly lowered the noise exposure. To pass the time, we wandered through the Formula One pit area and found a Maserati 250F warming its engine. This led to the highest noise exposure of the entire weekend, with a whopping 143 dB L_Cpeak  and sound pressure levels of over 116 dB(A) noted!

The afternoon was spent in the Raidillon grandstand, where a combination of tinny music and commentary through the PA system eliminated any chance of rest for the ears between races. The pre 1966 Grand Prix race was by far the loudest, with the pictured Maserati a clear winner for both best sounding and loudest car of the event.

The dosemeter only logs 1-minute LAeq data which masks the true drive-by sound level of the cars, but when the field was closely spaced, the dosemeter display registered sound pressure levels exceeding 110 dB(A). The overall measured sound level for this race was 95 dB L_Aeq,T, a full 10 dB higher than the following race.

Spectator histogram for Friday 26 September 2025 showing LAeq,1min and LCpeak values

Having enjoyed a full day of racing on Friday, we were content to spend more time infield on Saturday. The 6-hour race doesn’t commence until 4pm so we found ourselves in the paddock once again, where a Bugatti Type 35 warming its engine was no match for Friday’s Maserati. Even with our relaxed approach to spectating, we enjoyed a variety of races including Pre-War sports cars and an Alfa Romeo Cup which both yielded surprisingly modest noise exposure. Inevitably, we found ourselves in the bar, where rowdy voices, background music and distant racing yielded ambient sound levels of 80-85 dB(A). During this period, the chart for Saturday 27 September 2025 (overleaf) clearly shows a steady increase in ambient sound levels as spectators gathered for the big race.

Endurance racing pushes both car and driver to the limit and attracts only the hardiest spectators who are willing to sit outside until 10pm on a damp autumn evening. We passed the two hours until sunset on the pit mezzanine, experiencing drive by sound levels consistently above 120 dB L_Cpeak. A strategic leisurely dinner buffet halfway through the race had the potential to give our ears a break, though levels in the busy dining hall averaged 80 dB(A) which is too high for an effective rest area.

The night brings added intensity to the racing, with cars identifiable only by their headlights and exhaust note. To stave off the cold, we walked the length of the Kemmel Straight all the way to the semi-circular Bruxelles corner. Unsurprisingly, Kemmel gave our highest single minute of exposure of the day (103 dB L_Aeq,1min), where the fastest cars were comfortably exceeding 160mph as they passed by.

Spectator histogram for Saturday 27 September 2025 showing LAeq,1min and LCpeak values

In answer to the question ‘how loud is…historic motorsport’ an exhausting 12-hour day of motorsport resulted in an overall exposure of 87 dB L_Aeq,12hr. Our exposure on the day before was higher still, at 91 dB L_Aeq,_8h.

To put this in context, guidance in the WHO “Environmental Noise Guidelines for the European Region” 2018 suggests that we should aim to reduce the yearly average from all leisure noise sources combined to 70 dB L_Aeq,24h. Converting the motorsport noise exposure over the weekend to a yearly average (assuming 365 days) equates to 62 dB L_Aeq,24h.  Attending more than six weekends of historic motorsport in a year (without hearing protection) would cause this guideline level to be exceeded, based on the results of this investigation – and assuming no other elevated leisure activity noise exposure throughout the year.

In conclusion, regular attendees of historic motor racing events should remember to pack their hearing protection!

The draft version of BS 8233 was published in June 2025. This standard is one of the most important documents relating to acoustics, and is often used by acoustic consultants and environmental health officers / planners respectively – particularly with regard to the setting of internal noise limits for new residential development.

Part of the work that WBM undertakes for our mineral clients is the reviewing of planning applications for residential developments near to industrial / mineral related sites – which often refer to BS 8233.

The draft standard contains major changes compared to the existing version of BS 8233. Some examples of the main changes with regard to dwellings are listed below:

• The guidance for new dwellings relates to external noise from transportation sources only
• There is no differentiation between different types of rooms
• The approach for dwellings is to categorise the external noise, depending on type of transportation noise and magnitude, and provide a composite sound insulation performance for façades based on the external noise category – although some internal level targets are provided
• External noise affecting dwellings is defined in terms of the Lden and Lnight
• Internal level targets in dwellings are in terms of Lden
• There are no longer any noise level targets for external amenity areas
• There is negligible guidance provided when dwellings are exposed to other types of non-transportation noise (such as commercial/industrial sources), with limited reference to BS 4142 or the ‘agent of change’ principle

WBM has numerous concerns about the draft standard and will be responding formally on the consultation.

Please get in touch if you need a weblink to access the draft standard.

The end date for public comments is 06 September 2025.

Environment Agency ‘Method implementation document’ for BS 4142

The Environment Agency has published a ‘Method implementation document’ (MID) about BS 4142:2014+A1:2019 (BS 4142). This document sets out the Environment Agency’s requirements for BS 4142 assessments that are submitted for a new permit or varying an existing permit

The MID was published in March 2023 and updated in December 2023.

Part of the Environment Agency requirements are that the background sound must not include existing site sounds. During noise measurements, all site activities should be reduced where they no longer contribute to the background level and where they cannot be heard at the measurement location. The background sound level must not include any sound from the site.

This can be problematic for existing sites with current operations. The Environment Agency suggest that the site temporarily stops any noisy operations, or the use of a surrogate monitoring location (with justification).

In addition, the Environment Agency requires the BS 4142 assessment to consider all sound from a site, not just the new or increased portion.

WBM has undertaken many BS 4142 assessments for sites seeking new or varied permits, providing information to comply with the Environment Agencies requirements.

The links for the MID, and also for the noise and vibration requirements for environmental permits are provided on WBM’s website, see:
https://www.wbm.co.uk/documents/

WHO Guidelines 2018

The World Health Organisation (WHO) Europe has published the WHO Environmental Noise Guidelines for the European Region (2018) as a regional update and to provide an important replacement of the 1999 Guidelines.  The main purpose of the 2018 guidelines is to provide updated recommendations for protecting human health from exposure to environmental noise from transportation, wind turbine and leisure sources, based on recent research.

WBM is attending an Institute of Acoustics conference in January 2019 to keep up to date and be involved in the discussions about the implications of this important WHO document.

In the meantime, our summary of the WHO 2018 guidelines is available here: WBM WHO 2018 Summary Nov 2018

A full version of the 181-page document is available here:
http://www.euro.who.int/en/publications/abstracts/environmental-noise-guidelines-for-the-european-region-2018

A shorter, 8-page Executive Summary of the 2018 guidelines is available here:
http://www.euro.who.int/en/health-topics/environment-and-health/noise/publications/2018/environmental-noise-guidelines-for-the-european-region-executive-summary-2018

BREEAM 2018

BREEAM New Construction has been updated from 2014 to 2018 for the UK. The issues relevant to acoustics are Hea 05 Acoustic Performance and Pol 05 Reduction of Noise Pollution.

Hea 05 Acoustic Performance ensures that the new building is capable of providing an appropriate acoustic environment for users. Up to 4 credits are available for residential institutions and up to 3 credits are available for other building types.  The credits are awarded when a building meets the appropriate acoustic performance standards and testing requirements for sound insulation, indoor ambient noise level and room acoustics.

For Pol 05 Reduction of Noise Pollution, 1 credit is available for avoiding or reducing the impact of external noise arising from fixed installations from the new development on nearby noise sensitive buildings.

WBM can provide assistance on BREEAM assessments for Hea 05 and Pol 05 for the 2018 or earlier versions of the document.

Building Regulations Approved Document E amended 06 April 2015.

There is now an Amended Approved Document to support the following requirement of Schedule 1 to the Building Regulations 2010:

PART E (RESISTANCE TO THE PASSAGE OF SOUND)

See: http://www.planningportal.gov.uk/uploads/br/BR_PDF_AD_E_2015.pdf

The main change made by the 2015 amendment, which is in force from 6 April 2015, is an update to the reference to standards for schools. This is stated in Section 8.0 of the document, where it no longer refers to Section 1.0 of the 2003 version of BB93, but now refers to “Building Bulletin 93. Acoustic Design of Schools: performance standards”.

There is no document date stated and therefore the most recent version applies, which is currently version 17 (February 2015) as noted in WBM Technical Update 12 February 2015.

See: https://www.gov.uk/government/publications/bb93-acoustic-design-of-schools-performance-standards

The application and consequences of these documents are at an early stage and we would be happy to discuss the potential implications for any of your projects.

We thought that the following quick review of three recently published technical documents relating to acoustics would be useful.

A revision of British Standard BS 4142 “Methods for rating and assessing industrial and commercial sound” was published at the end of October 2014 and replaced the 1997 edition. The 2014 edition clarifies the use of the standard and includes good practice for reducing uncertainty. The execution of its provisions will be entrusted to appropriately qualified and experienced people to inform decisions made by other professionals.

The Institute of Environmental Management & Assessment produced “Guidelines for Environmental Noise Impact Assessment” in October 2014. The guidelines define core methods and techniques, used within the noise impact assessment process, relevant to all types and size of development. The guidelines present current good practice methods and procedures to assist in determining the degree of significance of the potential noise impact from a proposal.

With regard to schools, the much awaited replacement to Building Bulletin 93 (BB93) 2003 “Acoustic Design of Schools” has emerged, with version 17 (February 2015) the latest. The acoustic performance requirements in the latest BB93 are broadly similar to the 2003 edition although there are differences, some of which are outlined below:

• More stringent performance requirements for children with special hearing and/or communication needs
• Rain noise now requires assessment
• Performance values are provided for refurbishment as well as new build

The application and consequences of these documents are at an early stage and we would be happy to discuss the potential implications for any of your projects.