# Using Virtual Soundwalk Approach for Assessing Sound Art Soundscape Interventions in Public Spaces
## 4 Discussion
### Limitations of the Study
#### 4.1.1 Sound Source Identification and Perceptual Attributes  
The identification of sound sources added by soundscape interventions and natural sounds of flowing water proved to be an issue across all the locations where they were not perceived as dominant. Besides the electroacoustic intervention, the measurement point B2 was possibly influenced by some limitations of Ambisonics decoding and FOA recording, such as aliasing [82]. Although the researchers observed significantly more natural sounds at the point B2, the prominent sound of the rough river Mur probably contributed to the impression of noise and the participants most likely attributed it to traffic, despite of different localization (traffic in front, the sound of the rough river behind and below). This speaks against the use of FOA recordings in laboratory to assess water-based soundscape interventions distant from the listener, similar to findings by [PERSON] et al. [83] and opposed to the findings by [PERSON] et al. [84]. However, further research is needed on this as water features can vary greatly [51]. Results of the sound source identification revealed that the description of 'designed sound source' was occasionally misunderstood (location C), as well as the 'acoustic effect' (location A). Yet, the recognition of the echo effect at the measurement point C2 and the sound of the Sea Organ were successful and highly statistically significant, which led to the decision not to exclude any of the responses from the results. However, the ambiguous answers at other locations limited the possibility to investigate correlations between the recognition of these two sound source types and soundscape descriptors. Moreover, 315 s can be considered an overly long exposure time for this kind of experiment. While such duration was chosen to present the full duration of the sound source at the location B, it is likely that this did not improve its recognizability. The participants were allowed to start filling in the questionnaire during exposure as it was considered that it is a routine which does not affect critical listening, but it might have slightly decreased a possibility to recognize the sound source in question. At the same time, judging by the change of the perceived dominance of human sound sources at the measurement point B2, it can be said that its soundscape was most probably more influenced by the perceived dominance of sound sources other than the soundscape intervention. The significantly increased unpleasantness and lower calmness at B2 can be explained by significantly less perceived human sounds. This is one of the reasons why it is not possible to make a judgement on the influence the soundscape intervention had at that location. The changes in soundscape descriptor values were expected and they fit the model proposed by [PERSON] et al. [74] as introduced new sound sources at locations B and C contributed to the soundscape being less calm--introducing new sounds made them more eventful. At the location A both vibrancy and calmness increased from measurement point 1 to 2. Here, it must be noted that eventfulness itself was not revealed explicitly as significantly changed but rather manifested through the change in values for calm and/or exciting. That might speak in favor of assessing directly vibrant, calm, monotonous, and chaotic dimensions instead of assessing all eight descriptors as proposed within the Method A of the ISO/TS ISO 12913-2:2018 [31]. As no soundscape descriptor was identified as statistically significant across all measurement points, the possibility to investigate correlations with psychoacoustic measures was limited. Although the literature suggests that vibrant soundscape domain (eventful and pleasant) is often determined by non-auditory factors such as presence of people [85], it is interesting to note that this was not the case for the location C, where the social presence in both visual settings was very low (5 people visible at the picture representing C1 and 3 people visible at the C2).