## 2 Methods  
### Sound-Level Measurements  
The SPLs were measured at 12 different locations in a large shopping mall located in a very central location in Amman, Jordan. Amman is the capital city of Jordan. The population of Jordan is about 10.3 million, and around 4.3 million people live in the governorate of Amman [15]. The whole mall area is 124,000 m\({}^{2}\), and the area without parking totals 72,000 m\({}^{2}\). The number of occupied stores for the period of measurement was 125 stores, and the average number of mall entrances per month is 465,000 persons. The mall is designed with two atriums, where the largest atrium connects all seven floors with each other. For confidentiality, we have not used the mall's name. In this study, we divided the mall into four areas based on the uses of these areas: The first type of area is the shopping area, which consists of corridors surrounded by different stores. The customers walk along the hallways to enter their goal stores; the facades of the stores are of glass, and the ceiling is made of gypsum boards with metallic structures. The second type of area is represented by the entrances; these areas are similar to the shopping areas in their wall cladding, but with large automatic glass doors. The third area is the food court--a large common seating area surrounded by food service stores; the floor is made of granite or ceramic tiles, the tables are wood covered with Formica, and the chairs are made of wood or plastic. The fourth type of area is the playing area, which consists of a soft floor covered with carpets and a large number of electrically driven metallic playing machines, such as swings, horse carousels, etc. For each area type, we collected measurements at three different locations. Figures 1 and 2 show sample maps of the food court and the ground floor to demonstrate an example of the location of the SPL and reverberation time (RT) measurements. The measurements were collected four times each day (Morning: 10:30-12:30, Midday: 13:30-15:30, Afternoon: 16:30-18:30, and Evening: 19:30-21:30) for a whole week. A total of 48 measurements were done daily, each over a period of 180 s (3 min). A class 2 sound level meter was used, with a three-minute-long measurement, during which the meter saved an L\({}_{\text{A}}\) measurement twice a second (every 500 ms). The sound-level meter was about 1.35 m from the ground level and at least 1.5 m away from the surrounding reflecting surfaces. The meter was calibrated with a 94 dB acoustic calibrator. Equivalent sound-pressure levels were obtained for each record, and then the equivalent to the three records in each area of use was calculated, using Equation (1), where P1, P2, and P3 are the three measurement locations. \[\text{L}_{\text{Aeq}}=10\ \text{log}\ \frac{1}{3}\times\left(10^{\frac{\text{L}_{ \text{Aeq}}\text{P1}}{10}}+10^{\frac{\text{L}_{\text{Aeq}}\text{P2}}{10}}+10^{ \frac{\text{L}_{\text{Aeq}}\text{P3}}{10}}\right)\text{dB} \tag{1}\]  
A sample of 60 s of measurements from the food court at the three locations is shown in Figure 3. The sample measurements are for Friday (weekend day) afternoon. It is clear from the sample, that in position 3, the L\({}_{\text{Aeq}}\) are higher than the other two locations, which is likely due to the location near the food court entrance and the location near the ice cream shop, which have ringing bells and employees shouting about their products at various intervals. To measure the L\({}_{\text{Aeq}}\) contributions from background music, air-conditioning, and other sources apart from the customers, early morning measurements were performed after opening the mall. These measurements, done on Monday morning, are considered background noise for the shopping areas and entrances, since the mall has a minimal amount of traffic on Monday morning. For the food court and the playing area, Friday early measurements are considered background noise, as the stores in those areas are all closed at that time.