## 2 Methods
### Method for Assessing the Acoustic Environment and Soundscape
#### 2.3.1 Acoustic Parameters  
In each of the ten places, one or two acoustic measurement points were established, in accordance with the size of the area and the spatial variation of the sound levels in the analysis units.  
The acoustic environment was then assessed through noise measurements. The overall measuring time in the places considered was 1 h and 30 min for different assessment periods (day or evening), at 2 m from the ground.  
The following indicators were recorded using Bruel & Kjaer Type 2260 Class 1 integrating sound level meters: \(\mathrm{LA_{eq,1s}}\), \(\mathrm{LA_{max}}\), \(\mathrm{LA_{min}}\), and the percentiles LA10, LA50, and LA90. Additionally, the technician taking the measurements identified any sound events and noted its source.  
From the measurements taken in each place, during post-processing, acoustic data were extracted every 10 min [28], with the following indicators being obtained: \(\mathrm{LA_{eq,10 min}}\), \(\mathrm{LA_{min,1s}}\), \(\mathrm{LA_{max,1s}}\), \(\mathrm{LA10}\), \(\mathrm{LA50}\), \(\mathrm{LA90}\), and total events.  
To identify events in post-processing a method based on the principle of dynamic thresholds was applied. This method compares the instantaneous level \(\mathrm{LA_{eq,1s}}\) with the energy averages of the \(\mathrm{LA_{eq,5s,downstream}}\) (5 s earlier) and \(\mathrm{LA_{eq,5s,upstream}}\) (5 s later). This way, a sound event is detected when noise level variation implies a difference with both downstream and upstream averages that exceed the threshold. For a sound event to be perceived, it should theoretically be greater than 10 dB of continuous noise and, in fact, there are procedures that use this threshold. The method used in our studies was designed to detect events caused by activities and sound sources characteristic of urban environments during the period of use by the public, i.e., the daytime. To this end, the initial studies analysed various options to define the dynamic threshold to be applied during post-processing of the time span of the sound levels recorded. Considering the acoustic levels and their variation in these particular acoustic environments, it was concluded that a dynamic threshold of 6.5 dB allows the detection of a number of events similar to the perception of the sound environment by the technician who was taking the measurement.  
In addition, according to the sound source that originated the events, the expert technicians classified them as positive, negative or neutral [28]. In this way, sources considered natural and those involving social interaction were ranked as positive, while mechanical and industrial noise (e.g., traffic) were set as negative. Finally, those which were perceived differently depending on the listener were considered neutral. From the positive and negative events identified in the timeframe of the questionnaire, the balance of events was calculated as the difference between the number of positives and negatives. Thus, a positive balance means a higher ratio of positive events and vice versa.  
The number of sources perceived is a variable that is used to describe the acoustic environment. Therefore, the participants were also asked to identify all the sound sources perceived and classify them as pleasant or unpleasant. Next, the source balance was calculated as the difference between the amount of pleasant and unpleasant sources; a positive balance indicates that there are more pleasant sources than unpleasant ones.