# Using Virtual Soundwalk Approach for Assessing Sound Art Soundscape Interventions in Public Spaces
## 1 Introduction  
This study was conducted with the aim to investigate how a range of sound art installation techniques (passive and active) introduced to public spaces can be assessed using the framework outlined by the ISO 12913 Acoustics-Soundscape series and post hoc laboratory listening tests. So far, soundscape interventions have been extensively looked into when introducing natural sounds [1; 2; 3] or generic music [4; 5], while sound-art-focused studies often featured electroacoustic installations commissioned for the research purposes without a detailed report on the acoustic and psychoacoustic characteristics of the very sound sources introduced [6; 7; 8; 9]. On the other hand, it is not always feasible to conduct a soundscape assessment in the design stage. Therefore, this study proposes a simulated soundwalk as a tool for exploring soundscape interventions which are already built, where a baseline condition equivalent is achieved by selecting a measurement point further away from the intervention position. The'soundscape approach' was developed complementary to the 'noise mitigation approach', focused on resolving serious environmental noise issues which affect population health [10] (including sleep disorder [11], learning impairment [12], heart diseases [11; 13], increased diabetes risk [14], and annoyance [15]) and economic factors, such as real estate value [16]. Still, the connections between soundscape as a perceptual construct [17] and health effects are under investigated [18]. Quality ofurban open spaces is an indicator for quality of city life [19], yet urban spaces are generally highly exposed to urban noise sources, i.e., the streets often being the very source of motor traffic noise, which is also the source which has the highest impact on population's health [20; 21]. On the other side, lowering sound pressure levels were proved to be insufficiently effective for achieving acoustic comfort [22]. For these reasons, analyzing perception of both positive and negative sound sources, overall quality of acoustic environments and its relations with non-auditory factors has been largely investigated within the soundscape discourse [23; 24; 25]. Recently, it has also been looked into finding means of successfully using qualitative and quantitative indicators to achieve acoustically pleasing spaces [6; 26; 27]. The psychological tool for soundscape assessment widely spread amongst the soundscape research community is a Swedish Soundscape Quality Protocol (SSQP) [28], built in the Method A for soundscape data collection of the ISO/TS 12913-2:2018 [29; 30]. In its structure and concept, it is identical to the SSQP [31]. It was structured to: (1) identify sound source types (human, natural and noise) present by assessing their perceived dominance; (2) define the main perceptual quality of the soundscape in question; (3) define the appropriateness of the acoustic environment to the visual experience; (4) assess the overall quality of the place. Method A relies on a soundwalk in situ, one of the main soundscape research tools [6; 25; 26; 32]--an act of walking through a setting with a focus on critical listening to the sounds that can be heard there [33]. In an urban environment, its aim is to collect audio data and grasp a mental representation of a city and its public space by combining soundscape with urban morphological features [34; 35]. It is used for both quantitative and qualitative analyses, by conducting soundscape assessment questionnaires and sound measurements and recordings, for further analysis [26]. It is considered to provide consistent data across different participant groups and across time [36], while applying approaches such as a two-directional path to reduce bias [37]. It can be conducted on-site [32] or in a simulated environment [38; 39]. It is not unusual that public space (especially closed commercial space) contains intentionally added sound sources to influence the mood of passers-by or to enhance its commercial appeal [40].