The Effect of Mosque Acoustic Design and the Surrounding Environment on Prayer Health in Riyadh City Post-COVID-19

The Mosques in Saudi Arabia have recently witnessed a remarkable development in audio systems. However, residents complain about the high sound levels. This research aims to measure the sound level and study the factors that affect the noise in the interior and outdoor environment, health and management. The research utilizes a sound measuring device to determine inside and outside mosque noise, distribute a questionnaire to prayers at different times during the day, including at peak times. Three case studies in Riyadh. The result shows that the indoor sound level is above 60 ± 7 dB, which is within the limit. The maximum outdoor value exceeded the 68 ± 20 dB limit, and the minimum outdoor value was 58 ± 18 dB post-COVID-19. The research recommends reducing the level of noise The research results will be applied to manage sound levels inside the mosques using smart devices.

 In mosques, the accepted sound level is 35 HZ, a depth of 4 m, and a frequency of 40 Hz [3].

Factors Affecting the Characteristics of Sound
 Sound from the source.
 Distance between the source to the prayer.
 The solidity of wall and ceiling material.
During the COVID-19 lockdown, mosques were closed for four months, then opened in August 2020. Thus, few prayers could pray at mosques [17]-50% of respondents prayed at home because of coronavirus fear.

Legislation
Reference [18] reported that Saudi Arabia's Islamic affairs minister is defending a contentious order restricting the volume of mosque loudspeakers, saying it was prompted by excessive noise complaints. The Islamic affairs ministry requested that speakers be set at no more than one-third of their maximum volume. Meanwhile, [19] discussed mosque construction in Sydney, stating it has a heavy construction approach. They report that designers should include social, cultural, and political aspects.

Objectives
1) Measure the sound level inside and outside mosques.
2) Study the space, material, and acoustic design.
4) Suggest smart solutions and smart maintenance at the technical and design levels.

Sound Meter
We used a Sound Level Monitor Aid in Noise Compliance smart sound monitor. The sound data were analyzed with Microsoft Excel. Figure 4 shows the meter used to measure the sound level in the studio class.

Distribution of the Survey and the Results
The survey was distributed to mosque prayers to determine their feelings regarding the sound level. The target was 100 respondents; only 20 respondents filled in the survey.

Statistical Analysis
We used SPSS statistical software to conduct one-sample t-tests for analyzing the data and measuring the mean values of the three case studies.

The Case Studies
The three case study mosques are located in one cluster in Al Rawdah 2, near Al Rawdah Park. Figure 5 shows the three case study locations in Al Rouda 2, Riyadh City, Saudi Arabia.  Figure 6 shows the location of case study one.    2) People are not able to hear the Azan at home.
3) Acoustic design needs revision in the selected case studies.

Results
The survey was distributed on 14/9/2022. The target group was the prayers in Al Rawdah 2 neighborhood. The target sample size was 100 prayers. Only 20 respondents filled in the survey.        Figure 16. One-sample t-test for case study 3. R2 Linear = 0.0447 and Y = 4.53 + 0.09X.

Results Justification
The results show that the maximum sound level inside the mosque exceeded the limit of hearing health (60 + 20 dB). The minimum sound level was acceptable (60 + 3 dB). However, [13] found that mosque noise levels were acceptable and in compliance with international norms of hearing safety from the National Institute for occupational safety and health (NIOSH; 85 dB). In addition, [22] found sound level reductions on the order of 6-7 dB during lockdown, with differences marked across sites and times of the day, after lockdown, sound levels gradually increased. This research record the sound level post COVID-19 and it found that the Max record exceed the limit in the outdoor environment ±20 Db this increase because of heavy traffic light near the mosques, and the Min in the indoor is exceed the limit 60 ± 7 (Table 12).

Discussion
The discussion focuses on the results of four main pillars of mosque design: acoustic design, interior space, outdoor environment, and health procedures and management post-COVID-19. The survey was distributed from September to October 2022. The target group was the prayers in the Al Rawdah neighborhood in Riyadh city. The target number was 100 prayers, but only 50% of the prayers responded. The research analyzed acoustic design in three case studies. We agreed with [21] that the research should analyze multiple case studies for better results. In this research, we analyzed three case studies.

The Acoustic Design
The respondents stated that they heard the Azan in their homes. Most respondents strongly disagreed that the Azan disturbed their sleeping patterns. In addition, most respondents heard the Friday Khotba in their homes. Most agreed that the voice was disturbing them at home and that the Azan helped them wake up early. Half of the respondents agreed that the Azan encouraged mosque attendance for praying. A few respondents agreed that the sound level disturbed them.

The Interior Space
Most respondents noted that children inside the mosque were not disturbing them. Few respondents found the children disturbing inside the mosque. However, most did not agree about this question. Most respondents agreed that crowding inside the mosque increased the sound level. All respondents agreed that the designer should use acoustic material and insulation in the wall. The research agreed with [7] that the three mosques need acoustic material studies.

Outdoor Environment
Most respondents agreed that the heavy traffic and cars in the outdoor environment increase the noise inside the mosque. In addition, the environmental conditions-especially the wind and sandstorms-in Riyadh city affect the noise inside the mosque.

Health and Management
Most respondents agreed that hiring a child keeper in the mosque is important, especially inside the female prayer area. Most respondents agreed to divide the space into different functional spaces for men, women, and children.
All the respondents agreed to use insulation materials in wall construction, such as a cavity wall or heavy construction walls with a thickness of 45 cm. In addition, using heavy carpets help minimize the noise inside the mosque. Most respondents agreed about using smart devices to hear the Azan at home.

Discussion of the Case Study Results
The sound level was measured with the help of two students using a sound meter to assess sound quality. In the jsd.ccsenet.org Journal of Sustainable Development Vol. 16, No. 4;2023 first case study, the indoor sound level had an average maximum value of 80 dB, while the average minimum value was 60 dB. The average maximum sound level for the outdoor environment was 68.8 dB, and the average minimum sound level was 55.04 d. This reflects the acoustic design quality based on the distance from the source. These results show that the sound level inside the mosque is high and exceeds the limit. Comparing the sound levels outdoors and indoors, the outdoor sound was lower because of the KSA legislation to limit outdoor microphones to 35 dB. By applying the SPSS t-test, the research found that the mean value for case study 1 was 67.27 dB, the upper value was 72.8 dB, and the lower value was 61.6 dB.
In case study 2, the results showed that the indoor average maximum value was 80.26 dB, while the average minimum value was 58.8 dB. The average maximum outdoor sound level value was 69 dB, and the average minimum value was 56.4 dB. These results show that the sound level inside the mosque exceeds the limit. When comparing the sound levels, the outdoor level was lower than indoors. The SPSS t-test found that the mean value for case study 3 was 65.9 dB, the upper value was 71.5 dB, and the lower value was 60.4 dB.
In the third case study, the indoor maximum average value was 67 dB, and the minimum was 66 dB, while the maximum level for the outdoor environment was 86 dB and the minimum value was 68 dB. By applying the SPSS t-test, the research found that the mean value for case study 3 was 75.15 dB, the upper value was 78.9 dB, and the lower value was 71.3 dB.
The results showed high maximum noise levels in the three mosques' interior spaces. The results agree with [8] that the acoustics inside mosques need revision. We also agree with [10] on the importance of studying the AC and air condition systems inside mosques. The research results agreed with [11] that the acoustic design inside the mosque exceeds the safe limit for human health.

The Health Impacts
Sleep disorders: Some neighbor's claimed that Azan affects their sleep.
Cardiovascular Diseases: Others said that the noise inside the mosque and from road vehicles is causing stress, high blood pressure, and heart attacks.
Hearing Problems: The microphone noise (60 ± 5 dB) may cause hearing problems.
Hearing Loss: Hearing loss is a handicap when someone has difficulty communicating in common situations, such as understanding noise around them. Such difficulties significantly affect the quality of daily life [20].

Noise Level Post-COVID-19
During COVID-19, the noise level reached 50 ± 5 Db [6]. This research measured the noise level in the outdoor environment; the maximum level was 68 ± 20 dB, and the minimum level was 58 ± 18 dB. The high noise range was because of heavy road traffic after the lockdown.

Conclusions
The Mosques designed in Saudi Arabia have the following acoustic design quality, with total area ratios of 1:3 and 1:2. The interior space is well equipped, the floor is covered by carpet, and the Emam and outdoor microphones are provided. The outdoor microphone sound level exceeded the standard 30-60 dB, according to LEED. Additionally, the acoustic maximum outdoor sound exceeded the limit in the three case studies (68 ± 20 dB) above the standard and minimum value (58 ± 18 dB) post-COVID-19 because of heavy traffic increasing the noise level inside the mosques. The HVAC system also affects the noise inside the mosque. The result shows that the indoor sound level is above (60 ± 7 dB), which is within the limit. The research recommends applying regular smart maintenance for HVAC systems. Additionally, children need to be safe and separate from prayers, so it is better to have a child keeper. The research encourages the regular recording of sound levels in the indoor environment using smart devices to minimize sound levels using acoustic material. For the people who do not hear the Azan at home, we recommend they use smartphone applications.