dBA Acoustics Survey and Consultancy

" ...There just aren't enough highly skilled professionals around that also provide value for money, particularly those that work in property/construction related industries. David handled every question, email, call with patience and consideration. Needless to say I'll never purchase or rent a property again without first consulting David and I feel very pleased to have found him... "
- Sisu Berhane, Archway, London

" I have worked with David over the years on a number of complex, time critical and high value projects. David has proven without a doubt to be an expert in his field and I would not hesitate in working with him again on future projects "
- Iain Jee, Head of Operations, Neptune Investment Management

" dB(A) Acoustics produced an acoustic assessment for a dance school planning application (Sept 2019). We worked with David, whose response to our enquiries was timely and he talked us through our requirements to ensure that we were taking the best approach. Their rates were also highly competitive for the services offered. We were dealing with a particularly militant planning authority that demanded a lot of detailed (in hindsight, disproportionate) information to support our application. David met these challenges head-on and supported us to address the council's concerns with the project. I'm pleased to say that we got a positive result and dB(A) Acoustic's work was instrumental to this. I recommend them wholeheartedly! "
- Liam N, Bromley

" We engaged dBA to perform a Noise Impact Assessment of a Temporary Chiller Installation.
David attended speedily, understood the requirement and carried out the assessment to a high standard. He subsequently produced a report that was very well presented and easy to understand. We would certainly use dBA again for similar projects "
- Tony Jackman, Head of Technical Services, Jaguar Building Services

" I was in desperate need of good sound-proofing for my surgery; this had
always been a problem, especially with patient confidentiality; we even had
to limit the number of patients in the building such that nothing could be
overheard. I consulted Mr Fernleigh; he covered all aspects of building
acoustics, outlining the structural "leaks". Everything was clearly
explained, even to a layman such as I. I received a detailed report and
was able to instruct my builder accordingly. The sound-proofing measures
have been excellent. I will most definitely be using Mr Fernleigh again on our next
surgery project; I cannot recommend him highly enough "
- Dr Simon Crawley, Rosewood Clinic, Surrey

Sound testing in London and the home counties, testing undertaken in Middlesex, Berkshire, Buckinghamshire, Hertfordshire, Essex, Kent, East Sussex, West Sussex, Surrey and Hampshire. Third party accredited for pre completion sound insulation testing for residential building regulations compliance. If you want sound testing carried out in London, the Home Counties or the South East of England then look no further.

Survey and noise impact assessment work is also regularly undertaken on behalf of acoustic consultancies and other colleagues within the sector.

dBA Acoustics has worked on many, many projects in London and the South East of England. The consultancy has experience and, although based in the South East of England, has reach working across the UK where necessary. The consultant services offered include acoustic survey, measurement, testing, calculation, assessment, design and specification work covering most sectors.

“ dBA Acoustics has just completed an acoustic survey for a Central London residential project, testing proposed floor coverings for a penthouse apartment. David liaised with downstairs’ neighbours, the freeholder’s surveyor, our main contractor & client. In all dealings, David was both utterly professional & completely amenable. He produced a comprehensive & unbiased acoustic report which has been invaluable in pushing this job forward. We would have no hesitation in contacting dBA Acoustics again for future contracts ”
- Alison Kan, Architect, London

Acoustic assessment can be required for various reasons, either to inform a design or comply with regulations. Typically, at the planning stage local authorities require evidence that a development will comply with their own, statutory or best practice targets and/or criteria. In this instance a noise impact assessment, usually in accordance with BS4142:2014, may be required. dBA Acoustics can undertake such assessments in a timely and efficient manner.

Many local authorities and particularly the London and other urban Borough's require a noise impact assessment carried out for new items of building services plant. Usually, at the initial planning stage but also retrospectively if installed items of plant and/or noise emissions subsequently become known to the Local Authority. In this instance once again a noise impact assessment, usually in accordance with BS4142:2014 is likely to be required. dBA Acoustics specialise in noise impact assessment in London and the South East of England.

Acoustic survey London, independent acoustic consultancy based in South East England.

Through the design phase Clients including many Developers and Contractors, seek design advice from qualified acousticians in order to confirm the likely performance of some aspects, or indeed a whole development. From ad hoc advice to RIBA Stage design reviews, dBA Acoustics is able to input into just part of the development process, or provide advice for the complete design, as necessary.

Additionally, when a development is commissioned prior to practical completion, acoustic testing may be required in order to demonstrate that the built conditions achieve those targets or criteria set out at the design stage. In this case acoustic testing will be required. This can be to the advantage of Contractors, Developers and Authorities as it not only shows that the development is compliant, but can also assist in identifying where shortfalls may exist and provide guidance for rectifying any shortcomings, should any become apparent. dBA Acoustics offers testing and troubleshooting services.

dBA Acoustics is third party accredited (SITMA sound testing scheme) to undertake pre completion sound insulation testing for the purpose of complying with the building regulations in new and converted residential developments. Sound testing undertaken in London and the Home Counties. Competitive prices quoted for sound testing in Middlesex, Berkshire, Buckinghamshire, Hertfordshire, Essex, Kent, East Sussex, West Sussex, Surrey and Hampshire. Fast turn around with report and results issued following the sound test.

“ Following the refurbishment of our flat, we needed a sound impact assessment carried out in order to obtain the end-of-work certification. We contacted dBA Acoustics for this. From our initial phone conversation and throughout the process we were impressed with David’s professionalism and expertise. He was very pleasant and patiently answered our questions offering helpful and detailed advice. The assessment and subsequent reporting were completed on time and efficiently. In summary, we highly recommend dBA Acoustics for its excellent service and competitive price ”
- Amir, Resident, Richmond upon Thames

Pre completion testing - Sound insulation testing

As of 2003, Building Regulations part E1 requires that all new or converted residential dwellings (including adjoined houses, flats and rooms for residential purposes) achieve certain levels of sound insulation. The required sound insulation performance can be verified in one of two ways. Either through the adoption and validation of specific construction details used in their construction, known as Robust Details. Or alternately, if Robust Details are not adopted, the sound insulation performance of the development must be validated by means of on-site pre-completion testing. If this approach is adopted, it is the responsibility of the builder to arrange for suitable on-site pre-completion testing to be carried out by a suitably qualified and accredited tester or testing body.

There are three types of sound insulation test: an airborne wall test, an airborne floor test and an impact floor test. A full set of tests is comprised of 2 airborne wall tests, 2 airborne floor tests and 2 impact floor tests. For up to 10 dwellings 1 full set of tests is normally required. Tests are not required for adjacencies that do not exist i.e. for flats where there are no separating walls I set of tests is normally comprised of 2 airborne floor tests and 2 impact floor tests. Similarly, for semi-detached houses where there are no separating floors, 1 set of tests would normally be comprised of just 2 airborne wall tests. Tests are undertaken only between adjacent habitable rooms (i.e. living rooms and bedrooms). The extent and location of the separating partitions to be tested is set out in the general guidance contained in Approved Document E but ultimately at the discretion of Building Control.

Procedure

The testing and rating procedure currently used is set out in the Standards BS EN ISO 140-4:1998; BS EN ISO 140-7:1998; BS EN ISO 717-1:1997 and BS EN ISO 717-2:1997

Pass or Fail?

Once testing has been completed a report and certification will be provided which can be submitted to Building Control. Should any part of the testing program fail to achieve the requirements then remedial measures will need to be implemented and re-testing undertaken to the satisfaction of Building Control.

“ We have been absolutely delighted with the quality and speed of David's acoustic design services. These have been applied to the refurbishment of a first floor1860's apartment in London, where we were trying to achieve acoustic isolation between ourselves and our neighbours above and below. This was not an easy task, particularly as we were trying to approximate Part E of the current Building Regulations - not easy in a 160year old building. The most impressive part of David's service has been the patience he has displayed in answering follow-up queries on site, and in supervising work on site, to achieve this standard. We have no hesitation in recommending David's services "
- Jonathan and Kaye, Residents, Blackheath, London

Experienced and trustworthy third party acoustic consultant offering invaluable survey, assessment, testing and design advice. Based in London and the South East of England and operating across the UK, dBA Acoustics is here to help.

In house testing and survey equipment is calibrated at least every two years to either fully traceable, or elevated UKAS calibration requirements. All sound level meters employed are Class 1. Clients can be assured that the instrumentation dBA Acoustics deploys is more than adequate for the task.

DBA ACOUSTICS LIMITED trading as dBA Acoustics
Company registration number 11713113 registered in England and Wales
Registered office: Suite 1, 1st Floor, 42 Alexandra Road, Farnborough, Hampshire GU14 6DA
VAT number: 197 6941 43

... and in case your were wondering about the background picture. It shows the massive 9 storey basement of the Caprice Gold, Istanbul, the first muslim hotel in Turkey, the largest hotel in Europe and purportedly 7 star rated! I took the photograph during a site meeting to discuss acoustic aspects of the internal building fabric and specifically the partitions separating bedrooms. Unfortunately, the project stalled not long before completion due to legal issues with the developer.

Independent acoustic consultancy services in London, the Home Counties and South East England, acoustic survey London, noise impact assessment London, sound testing home counties, acoustic design, plant noise assessment, noise assessment, noise impact assessment, sound insulation testing, pre-completion testing and more!

Working with many Developers, Architects, Contractors and Building Services Engineers, for example:

Acoustic Glossary

dB :
A logarithmic scale representing the sound pressure or power level relative to the threshold of hearing (ref : 20μPa).

Sound Pressure Level :
The sound pressure level is the sound pressure fluctuation caused by vibrating objects relative to the threshold of hearing.

Airborne Sound :
Sound that originates from, and travels through, the medium of air e.g. speaking voice, although it may subsequently travel through structure.

Impact Sound :
Sound that originates from, and travels through, structure e.g. footfall, although it may subsequently travel through air.

DnT,w :
The weighted (w) standardised (nT) sound level difference (D), a single number indicator of the on-site airborne sound insulation performance of a construction, usually measured across the frequency range 100-3150 Hz. The higher the value of DnT,w, the greater the sound insulation, and the more onerous the requirement. A spectrum adaptation term C, or Ctr, may be applied to the DnT,w

L’nT,w :
The weighted (w) standardised (nT) sound pressure level (L), a single number indicator of the on- site impact sound insulation performance of a construction, usually measured across the frequency range 100-3150 Hz. L’nT,w is usually specified as a maximum sound pressure level in the receiving room. The lower the value of L’nT,w, the quieter the received impact sound, and the more onerous the requirement.

Reverberation Time :
The time taken, in seconds, for a sound to decay by 60 dB. The longer the time taken for the decay, the longer the reverberation time. Reverberation generally differs with frequency and hence is normally measured in octaves (125 Hz-4kHz) or third octaves (100 Hz-5 kHz).

LAeq,T :
The equivalent continuous A-weighted sound pressure level defined IN BS4142:2014 as the value of the A-weighted sound pressure level in decibels of continuous steady sound that, within a specified time interval, T = t2 – t1, has the same mean-squared sound pressure as a sound that varies with time.

LA90 :
The background sound level as defined in BS4142:2014 as the A-weighted sound pressure level that is exceeded by the residual sound at the assessment location for 90% of a given time interval, T, measured using time weighting F and quoted to the nearest whole number of decibels.

LAmax :
The maximum A-weighted sound pressure level in a given time interval, T, measured using time weighting S (slow) or F (fast) and quoted to the nearest whole number of decibels.

Ambient Sound :
As defined by BS4142:2014 is the totally encompassing sound in a given situation at a given time, usually composed of sound from many sources near and far.

Specific Sound :
As defined by BS4142:2014 is the sound source being assessed.

Residual Sound :
As defined by BS4142:2014 is the ambient sound remaining at the assessment location when the specific sound is suppressed to such a degree that it does not contribute to the ambient sound.

Rating Level :
As defined by BS4142:2014 is the specific sound level plus any adjustment for the characteristic features of the sound.

Tonality:
An acoustic character correction from BS4142. For a prominent, discrete tone to be identified as present, the time-averaged LZeq,T sound pressure level in the one third-octave band of interest is required to exceed the time-averaged LZeq,T sound pressure levels of both adjacent one-third-octave bands by some constant level difference.
The level differences between adjacent one-third-octave bands that identify a tone are:
•15 dB in the low-frequency one-third-octave bands (25 Hz to 125 Hz); 

•8 dB in the middle-frequency one-third-octave bands (160 Hz to 400 Hz); 
and 

•5 dB in the high-frequency one-third-octave bands (500 Hz to 10 000 Hz). 


Impulsivity:
An acoustic character correction from BS4142. Noise events with a rapid onset or subjectively sudden initiation. The faster the onset rate and greater the magnitude of sound pressure level, the more prominent the impulsivity.

Intermittent:
An acoustic character correction from BS4142. When a specific sound has recognisable on/off conditions over the reference time period (rather than being "always on" for example).

VHF : an acronym for Very High Frequency when used in relation to radio waves designates signals from 3 to 30MHz and considerably higher than the upper threshold of human hearing.

VHFS : similar to the above though when in used relation to sound pressure i.e. Very High Frequency Sound: used to refer to sound that is in the upper range of human hearing e.g. 10-20kHz.

Lday :
The A-weighted long-term average sound level as defined in ISO 1996-1: 2016, determined over all the day periods of a year.
Levening : is the A-weighted long-term average sound level as defined in ISO 1996-1: 2016, determined over all the evening periods of a year.

Lnight :
The A-weighted long-term average sound level as defined in ISO 1996-1: 2016, determined over all the night periods of a year.

Lden :
An average sound pressure level over a whole day, evening and night, a compound indicator of the above mentioned Lday, Levening, and Lnight with penalties of +5dB and +10dB for evening and night time periods respectively.

HTM 08-01 Health Technical Memorandum: Acoustics: Department of Health requirements for the acoustic performance of health care facilities.

WHO :
The World Health Organisation.

BB93 :
Is Building Bulletin 93 “Acoustic Design of Schools: Performance standards” and sets out the minimum performance standards for the acoustics of school buildings.

IANL :
As defined in BB93 is the indoor ambient noise level within teaching accommodation and is comprised of a 30minute LAeq.

'A' Frequency Weighting:
e.g. dB(A), LAeq, LAmax. Derived from equal loudness contours, the commonly used weighting filter of the audible frequency range that accounts for the response of the average human ear to noise stimulus. This is the predominantly adopted weighting used in architectural acoustics and building services noise control.

'C' Frequency Weighting:
e.g dB(C), LCPeak. Less commonly used weighting filter of the audible frequency range used when determining peak sound pressure and accounts for tendency for the human ear's response to flatten off at high levels.

'Z' Frequency Weighting;
e.g. dB(Z), LZeq, LZmax. The flat frequency response of a measurement and essentially no weighting at all, formerly referred to as linear. Often used to examine octave or third octave frequency data.