Quantifying Sound levels for Sound Testing Failures

Quantifying Sound levels for Sound Testing Failures

APT Sound Testing often ask us about the parameters behind the sound testing under Part E. To try and clarify sound levels in more detail we have written a brief explanation.

What is sound or Noise?

Noise or sound  is often defined as unwanted sound. Sound is defined as any pressure variation heard by the human ear. The sound pressure level (SPL) is a measure of the air vibrations that make up sound. Because the human ear is sensitive to a wide range of pressure levels, the SPL is measured on a logarithmic scale with units of decibels (dB).


How do we  perceive noise or sound?

Healthy human ears perceive pressure variations over a wide range of frequencies — from low as low as 20 Hz to frequencies as high as 20,000 Hz. The human ear’s range starts at the threshold of hearing (0 dB) and ends at the threshold of pain (around 140dB) which would be the same as standing next to a large jet engine.

The human ear is less sensitive to sounds in the low frequencies compared to the higher frequencies. For example, a 50 Hz tone must be at a level of 85 dB in order to be perceived by the human ear as being the same loudness as the higher frequency 1000-Hz tone at a level of 70dB

How do you quantify sound?

As mentioned above, sound levels are usually measured and expressed in decibels (dB). Most environmental noise does not consist of a single frequency, but rather a broad band of frequencies differing in sound level. The intensities of each frequency add to generate sound. The method commonly used to quantify environmental sounds involves evaluating all of the frequencies of a sound according to a weighting system which reflects that human hearing is less sensitive at low frequencies and extremely high frequencies than at the mid-range frequencies. This is called “A” weighting, and the decibel level measured is called the A-weighted sound level (dBA).

Quantifying sound testing failures

As a rule of thumb, a doubling in the loudness of the sound occurs with every increase of 10 dB in sound pressure. In other words, for most individuals a 60 dBA noise would sound twice as loud as a 50 dBA noise.

If a sound testing fails, the client often asks by how much. When we confirm it has failed by 5dB they usually say ‘if that’s the case I only need to improve the partition by 10%’, unfortunately that isn’t the case – the partition has actually failed by 50% subsequently the partition will need major upgrades to pass the sound testing under Part E of Building Regulations.

APT Sound Testing can advise on all types of acoustic design, whether it’s accomplished during initial construction or during a refurbishment/renovation project.  We have the technical experience to help identify and rectify your soundproofing or noise control problem.

If you would like more information in regards to sound testing please follow our blog at: http://soundtestinguk.blogspot.co.uk or contact us at: info@aptsoundtesting.co.uk or visit our website at: www.aptsoundtesting.co.uk



We are often asked what types of sound test and noise surveys we can undertake. We offer all types of Sound Testing and noise surveys as well as design consultancy. Here is a quick summary of our acoustic services:

We are accredited to carry out Sound Insulation testing for:

  • Houses and flats in compliance with Part E of the Building Regulations.
  • Houses & Flats in compliance with the Code for Sustainable Homes.
  • All commercial buildings in compliance with BREEAM.
  • Classrooms within schools in compliance with BB93.

sound testing

We also try to provide a ‘one stop’ testing service for compliance with the latest Building Regulations. Our full ranges of services are:

Air Tightness Testing

  • Pre-completion Air Tightness Testing for residential and commercial buildings (Part L1&L2)
  • Air Tightness Design Reviews.
  • Combined Pre-completion Air & Sound Test (Part L1 & E) improves coordination and saves cost!

Sound Insulation Testing

  • Pre-completion Sound Testing for residential and school buildings (Part E & BB93)
  • Acoustic Design Consultancy (Part E & BB93)

Noise Surveys

  • Noise Surveys for planning (PPG24)
  • Noise Surveys for proposed air conditioning and other noise sources (BS4142)

Thermal Surveys

  • BREEAM Thermal surveys to show continuation of Insulation (Part L)
  • To locate leaks within roofs/walls and under floor heating. (Fault Diagnosis)
  • Annual Infrared Surveys on Electrical Switchboards and plant (Annual Maintenance)

Energy performance Certifications

  • Design Stage SAP & SBEM Certification (Part L)
  • As Built SAP & SBEM Certification (Part L)
  • Energy Performance Certificates (Part L)

Ventilation Testing

  • Ventilation Testing – now mandatory on all domestic ventilation systems (Part F)

Integrity Testing On Server Rooms

  • Integrity Testing on Server Rooms (rooms that have gaseous fire suppressant systems) – These must be carried out annually (ISO 15004)

UAV Aerial Surveys (unmanned)

  • Roof condition surveys on Residential, Factory and Church Roofs.
  • Thermal Surveys of Large Roofs.
  • Progress photos of large construction sites; i.e. at greenfield, foundations, envelope & completion stage.
  • Photos of completed dwellings and buildings for advertising purposes.
  • The Creation of 3D models of your project/site.

If you would like more information in regards to our sound insulation testing and/or air tightness testing packages, please don’t hesitate to contact us at: info@aptsoundtesting.co.uk or call Darren direct on 07775623464