## 4 Procedure
### Assembling the Equipment  
1. Set up the equipment by prioritizing the position of the 360\({}^{\circ}\) camera and position the lens at the average eye level 160-180 cm, as shown in Figure 2. It is advisable to test the setup for video stitching issues and reconfigure if needed (e.g., the equipment will be partially visible in the raw video recording, so you need to test if the chosen setup allows for efficient erasing/hiding/patching of the exposed parts in the post-processing). Companies selling 360\({}^{\circ}\) cameras usually offer free software for basic editing and previewing. It is advisable to position the camera as the highest item in the set to avoid the need for editing both the sky and the ground.
2. Carefully position the AMB microphone so its axes are aligned with the axes of the 360\({}^{\circ}\) camera; the microphone's front (usually marked by the logo) and the camera's front should be looking in the same direction. Many AMB microphones allow them to be oriented vertically or horizontally (end-fire), this should be noted and adjusted in the relevant software settings. This is essential for informed post-processing. It is advisable to position the capsules of the AMB microphone and the capsule of the SLM as near to each other as possible, without introducing scattering effects. It can usually be done within the same windshield unit, but it is not essential to do so and depends on the available clamps and stands.
3. The gain settings for the four ambisonic audio channels should be set to the same level. In some devices (such as the MixPre 10), this can be set by locking the channel gain settings to a  
Figure 2: Photo of a full survey carried out in a park in London during the Questionnaire Stage. To the left is the equipment (color-coded to match Figure 1), with the ambisonic microphone and SLM microphone in the windscreen, with the 360\({}^{\circ}\) camera on top of the tripod and to the right are one researcher interacting with the participant while the second researcher conducts the binaural recording. The body of the SLM and the multi-channel recorder are stored in a bag under the tripod which can contain all of the pieces of equipment for easy transport.  
single channel. Many devices also offer ambisonic plugins which simplify these settings and automatically link the gain settings--these should be used where available.
4. Set the SLM to log sound levels and simultaneously record.wav audio. The recommended logging settings are given in Table 3. The SLM should be mounted and positioned according to standard guidance for environmental noise measurements, like that given in Section 9 of ISO 1996-2:2017 [19] or Section 5 of ANSI/ASA S12.9-2013/Part 1 [50]. Generally, the microphone should be a minimum of 1.2 m above the ground and a minimum of 1 m from any vertical reflecting surfaces.
5. Attach the environmental meter(s) to the tripod. Care should be taken when positioning the environmental monitor. Most units will include guidance on their use from the manufacturer--these should be followed where available. Some general items to keep in mind include not accidentally covering air quality sensor holes, not positioning light sensors in the shade of the other equipment, and not positioning temperature sensors in direct sunlight unless this is how they are intended to be positioned.