When Heathrow Airport started an 8-week consultation on the airspace and airport future operations, between January and March 2019, we were briefed to help deliver meaningful, objective sound demonstrations to the affected communities.  

Information relating to changes in aircraft noise can be hard for communities to understand, and reading noise contours and decibel levels can have little meaning to those who are directly affected. To communicate the potential noise impact, our acoustics, virtual and visualisation teams developed three fully mobile Soundbooths equipped with virtual reality sound demonstrations, aimed at helping communities to:

  • Understand Heathrow’s proposals 
  • Work out what the proposals meant to them as individuals
  • Better engage in the consultation and decision-making process

We aimed to deliver the information in an engaging way and widen the demographic who had been reached at previous consultations.

The pioneering VR Soundbooths will pave the way for airports globally to consider the same approach in engaging with the public about noise issues. We believe that they define best practice in the communication of aircraft noise changes, providing significant societal benefits and helping communities to engage effectively in consultation and decision-making processes, such as the Airspace Change Process.

Integrating the immersive Virtual Reality

For the first time at an airspace public consultation level, the demonstrations were made available in an interactive virtual reality environment, which combined a virtual user interface, 360 video footage and 3D planes with detailed aircraft spatial audio recordings and different background ambient sound recordings. 

With some people living in areas that do not experience aircraft noise, having the information available in a virtual reality environment with immersive 3D visuals and head-tracked spatial audio provided an understanding of the potential impacts. It went beyond previous sound demonstrations to communicate the visual impact of being overflown as well as the sound of different operational aircrafts.

The demonstrations were delivered with an innovative 3D menu system that utilised elements of augmented reality, allowing users to operate the demonstration’s selection menu with their hands. To engage with a wide range of demographics, the interface was designed to be easily accessible and operational, catering for all ages. A touchscreen version of the demonstrations was made available to accommodate those who were unable/unwilling to use virtual reality headsets. Most consultees decided to use the Virtual Reality version of the demonstrations. 

The same augmented reality was used to allow users to interact directly with the demonstrations themselves, so they could ‘toggle’ between different sounds (e.g. with and without sound insulation) in real time.

Leveraging our SoundLab to design sound-proof booths 

The Soundbooths needed to be deployed at consultation events, a very busy and noisy environment with sound-controlled booths therefore a key focus. We worked closely with Strata to undertake controlled listening tests in our SoundLab™ facility. This included simulating the expected reverberant noise levels from a busy consultation event and using this experience (a purpose-built sound booth for acoustic assessment) to define a required sound insulation performance for the Soundbooths. Acoustic tests of the sound insulation performance were then carried out, both before and after fit-out, to confirm the required performance was met.

Uncompromising accuracy and reliability 

Sound demonstrations accurately recreate existing or predicted sound environments, with our sound demonstrations based on audio of aircrafts operating at Heathrow. Similarly, the sound level was measured using a Type 1 sound level meter to ensure that sounds could be played back at the correct level. The recordings were then converted to a headphone-based audio system known as ‘binaural audio’ allowing the spatial distribution of the sounds to be experienced over headphones.

Each set of headphones was calibrated before demonstrations, a crucial aspect of the Quality Assurance procedure. Combined with rigorous technical reviews and verification, this ensured that what was being heard by the listener copied the scenario being demonstrated to a high level of accuracy.

For ultimate reliability, we engaged with the Noise Expert Review Group (NERG) throughout production. Its members have extensive experience in different aspects of acoustics, noise and health, and aim to provide independent assurance of the scientific and policy strength of the assessment and mitigation of sound, noise and vibration. including effects on health and quality of life.

All good things come from successful collaborations

Delivering the project within 12 weeks without compromising the quality of the experience was a challenge to the team. The project’s success was down to the excellent partnership between Arup and Heathrow, and the flawless collaboration with Strata. The demonstrations were designed simultaneously to all other consultation materials, allowing the project team to save considerable time. This required careful liaison with the process’s different consultants and necessary close collaboration with our project partner Strata during the rapid design stage, ensuring Soundbooths were created to meet the required acoustic criteria. Care was required to provide a demountable and robust solution that could be toured between the venues.

I think the Soundbooths have been a really popular addition to the consultations that have been ongoing now for about a year because they take a very complicated topic and give a real reference point for the conversations that we have with members of the public

Emma Gilthorpe

Director for Expansion, Heathrow