- Understanding aviation noise
- Improving impact management
- Communication and engagement
There are some virtual reality applications (auralisation and visualisation) which can be used by residents to give them better understanding of the impact of future airport scenarios in land-use planning, as the virtual reality creates high immersion for the user. Virtual Reality headsets feature a greater field of view than projector or TV screen. Additionally, using head-tracking sensors, they allow the system to change the visuals in a way that allows the user to look in all directions. The same is true for the (spatial) sounds that are produced and provide audio-directivity. But this immersion has to be ecologically valid if authorities want to be trusted by residents during communication campaigns.
Validation of a Virtual Reality application for aircraft noise
The NLR Virtual Community Noise Simulator (VCNS) is an innovation to support airport communities and other stakeholders who want to experience aircraft noise in their own environment by using the latest virtual reality technologies with 360 degrees video and 3D audio experience. The current set-up makes use of the shelf hardware, such as an Oculus Rift CV1 VR headset, supported by a powerful laptop computer, and separate headphones for the audio.
Artist impression, Virtual Community Noise Simulator by NLR
Participants of the study took part in a perceptual experiment. Two landscapes were presented in which the participants evaluated the flyover sounds and visuals of three distinct aircraft. These three aircraft are the Airbus A320neo, the Airbus A380, and a revolutionary design called the “BOLT” (Blendedwing body with Optimised Low-noise Technologies). The influence of the visuals was measured by presenting the sound of one aircraft with the visuals of the other aircraft as well. In one additional condition, the visual was not visible and this was represented by an overcast sky.
The “BOLT” architecture (source: EU ATREM Project; Roma Tre University)
In order to test if the size of the aircraft (or the absence of the aircraft vision because of clouds) has an influence on the perception of the audio-visual situation, all synthesised sounds were crossed with all visual situations. So, twenty-four environmental situations were created (three types of aircraft sound x four types of visual aircraft source x two types of landscape). The four types of visual aircraft source correspond to the three aircraft plus one situation with clouds in the sky. The two landscapes correspond to one green park, and one urban situation.
Landscape screenshots used for the laboratory study
People were immersed in these twenty-four situations. After each flyover, they had to use the joystick on the touch controller to give answers to a questionnaire which appeared in the virtual world.
Question about the audio-visual situation in the virtual world
A short video presents one flyover followed with the questionnaire as it appears in the virtual environment:
Participants felt surrounded by the environment as they are in real situations and the results showed that this virtual reality tool could be used for communication with residents around airports in a fair approach.
Effectiveness of this Virtual Reality application for better communication
In order to test the effectiveness of this simulation tool, two focus groups have been organised in the city of Beauchamp 20 km away from Roissy Charles de Gaulle (CDG) airport where an operational change of the aircraft route is planned in 2023.
During the workshop, the change affecting the approach operations was presented. This change has been introduced first following a classical communication approach, then following the novel communication method using the VCNS simulator.
The classical method consists in an oral presentation with a few slides showing the change on maps. The novel approach consists in inviting each participant to use the VR equipment. The VCNS showed two aircraft flyovers approaching CDG airport. The first flyover follows a stepped approach corresponding to the current standard. The second one follows a continuous descent approach which should become the new standard around CDG airport in 2023.
Diagram illustrating the difference between the stepped approach and the continuous descent for operations around CDG airport in France (source: DGAC (French Civil Aviation Authority))
The main objective is to assess whether visualising the change thanks to the VCNS helps communicate towards residents.
For the workshop, only one aircraft model has been used for the experiment, the AIRBUS A350. With this aircraft model, participants were able to visualise and hear the differences between the two trajectories in switching from the one to the other.
Participants felt the slight difference between the two simulations using the VR headset.
Their feedbacks are summarized below showing that the use of VR technology to simulate a future airport scenario was overall very well appreciated.
Mind Map as an illustration of the focus groups’ outcomes (click to enlarge)
They agreed that the VR is useful to experience the real difference between two approaches. Overall they assessed that the tool is realistic, and they rely on it for simulating different flyover scenarios.
The VR tool was complementary with map classical presentation because it provided credible simulations on which users relied on in demonstrating the change. Even subtle differences in sound (2 dB difference in max SPL) were perceived thanks to a relevant feature of the VR tool allowing to switch between two configurations instantaneously.
Both the laboratory experiment as well as the in situ study confirmed that this tool could be used around airports to better communicate with residents.