## 3 Techniques for Field Data Collection
### Contextual and Environmental Factor Data Collection
#### 3.2.1 Spatial Audio-Visual Recordings  
In order to capture the acoustic and visual information in the space for replication in a laboratory setting, 360\({}^{\circ}\) video and AMB audio are recorded to be used in Virtual Reality (VR) playback. The goal of this is two-fold: first, to enable researchers to document and replicate the in situ environment of the space as it was during a questionnaire survey session for lab experiments and, second, to capture environments in which performing a questionnaire survey is not feasible.  
Typically, questionnaire surveys are carried out over a period of several days at the same location. The goal of these multiple sessions is to capture as many questionnaire responses as needed (100 for a particular soundscape is typically recommended [11]), which, in the experience of the authors is prohibitively difficult to achieve in a single session in most locations. It is recommended that the repeated sessions are conducted under similar circumstances and environmental conditions. As such, it is not entirely necessary to repeat the spatial recordings each time a questionnaire survey is conducted. Instead, it is useful to use the spatial recording as a chance to gain a different perspective on the space under investigation. For instance, if the questionnaires are conducted in the middle of a large urban park, the first session could collect a spatial recording within the environmental unit of the questionnaire site, but the subsequent returns to the site could collect spatial recordings in a different environmental unit, say, along a road bounding the park, or in a space in the park which does not typically have many people. This enables the simultaneous expansion of the questionnaire database and the gathering of additional environments to investigate in a laboratory setting.  
General notes for spatial recordings:  
* The audio-video recordings can be done before or after the questionnaire survey.
* The purpose of the audio-video recordings is to capture representative recordings which can be reproduced in a laboratory setting. During the first time at a location, the focus should be on capturing the environment as experienced by the respondents to the questionnaires at that location. Therefore, the recordings should be performed in nearly the same spot, with similar lighting and environmental conditions. For further survey sessions, provided the conditions are similar, other recordings could be taken which provide additional perspectives around the space for reproducing in the lab.
* These recordings can be performed entirely separately from the questionnaire survey, if desired. Reasons for doing this may be (but are not limited to): location is not populated, making questionnaires impossible; specific locations or conditions are required for a lab experiment; time limitations require many sites in an area to be captured and in situ questionnaires could not be completed in time.
* The 360\({}^{\circ}\) video will take a significant amount of storage space. Researchers should ensure that there is ample free space on the camera SD cards prior to going out on site. If conducting multiple surveys away from their home institution (i.e., in another city), teams are recommended to bring a large external hard drive so that videos can be offloaded after each session.