The Role of Sound on Spirituality in Religious Environments and Islamic Architecture by Using EEG.

This present study aims to investigate the effects of the sound pressure level on mosque users' brain waves in the interior of the Nasir al-Mulk mosque in Shiraz. The research hypothesis is based on the fact that the sound pressure level is significantly related to the spiritual sense in the environmental psychology of the mosque. According, in the first step, a survey method is applied, the population of experts is formed, and sound characteristics are ranked using a questionnaire and Friedman's test. Next, the sound pressure level, which obtained the top rank, is selected to be tested and examined. In the second step, using a laboratory method and a brain wave recording device, 6 sound intensities indices were simulated and prepared in the software to carry out the test. The sound used in the present study is "Adhan" since the case study is an Islamic mosque. The test was done in the laboratory and a quiet room. To do the tests, the subjects were asked to sit and the sound was played through headphones for them. The 360-degree image of the mosque was shown to the subjects through virtual reality glasses, and finally, the data obtained from the brain waves recorded by special devices are prepared for review and analysis. The general results of the first step showed that among the characteristics of sound that are effective in creating/enhancing the spiritual sense in the architecture of mosques, sound pressure level obtains the highest score, followed by sound concept, the amplitude of sound, sound quality, sound source, and sound type, respectively. Also, the general results of the analysis of users' brain waves in the second part showed that sound pressure level (40-45 dB) is the most effective level in creating/enhancing a spiritual sense in the Nasir al-Mulk Mosque in Shiraz.