# City Ditty: An Inmersive Soundscape Sketchpad for Professionals of the Built Environment
## 3 Evaluating City Ditty with a Usability Study
### User Engagement  
Once a suitable virtual built environment is available, what would encourage PBEs to regularly engage in soundscape design with it? Through the lens of presence, many examples were already identified which may hinder engagement. For example, breaks in plausibility disrupt their workflow, while blurry spatial audio may cause discomfort. However, when the environment responded to the user's actions in realistic ways, this may generate interest and promote further exploration of other sound implications from both contextual and intentional design decisions. Such actions lay at the heart of this tool--to promote an interest in sound awareness, and to let PBEs explore and experience the acoustic consequences of their actions in a fleshed out urban context. To help analyze this further, the user engagement model [38; 43] is used to explore the different factors of user engagement. This includes aesthetic appeal (AE), focused attention (FA), perceived usability (PU), and reward (RW). This also incorporates and replaces the 'Desire to interact with the virtual environment' and 'Concerns for operating new software and hardware' themes, as participants have now had a chance to experience these firsthand. **Aesthetic appeal (AE)**  
Aesthetic appeal heavily overlaps with presence's immersion. This qualitative data suggest a bidirectional relationship where greater aesthetic appeal can contribute to greater sensory immersion (and therefore presence), while higher immersion can also lead to greater user engagement. **Perceived Usability (PU)**  
Perceived Usability varied according to a user's skill level. Participants P02 through P05 all rated this highly, as although they experienced several usability issues, they were quickly able to adjust and continue relatively unimpeded. However, P01 and P06 rated this lower for different reasons which gave valuable feedback. P01 was already experienced in both soundscape and video gaming (including city building games), and as such, was looking for a more polished, less guided experience. Indeed, half-way through the sound awareness session, P01 stopped following the instructions entirely and started a free design of their own using a lot of the functions that had yet to be introduced. [P01]: _\"I don't like tutorials [laughter]. I just wanted to say like, OK, OK, let me just play the game. I know the text is very important because you need to share some ideas about the soundscape, but I think some people will behave like me.\"_  
After a 6-minute detour of rapid exploration and free design, placing dozens of sound sources and trees, P01 quickly clicked through most of the remaining tasks (having already completed similar actions on their own), completing the entire session in 33 minutes. [P01]: _\"after half an hour I became a bit like I didn't want to do stuff anymore because it was a bit tiring, and I know that.\"_ P01 reported that it was taxing because it took too long to navigate through the menus for rapid prototyping. While it was very easy for them to place multiple objects of the same type in rapid succession, it was slow to switch between objects. As such, several interface designs need to be modified to facilitate future advanced users. On the opposite end of the spectrum was P06. They had zero history with navigating digital environments, playing games, nor did they have any experience with urban planning; they were a complete novice in every manner. They required a lot of guidance from the attending researcher and took a total of 73 minutes to complete the session--even skipping the final free design exercise. They also reported this as a very taxing experience, but for different reasons than P01. P06 reported difficulty navigating the 3D space, got lost within the space, and often second-guessed themselves and asked for support and reassurance. Despite the very slow start, P06 _was_ able to navigate themselves through the free design exercise at the end with very little intervention from the researcher, which indicates clear evidence of learning.