Evaluation of soundscape perception in open-semi open-indoor spaces of religious buildings: The case of Diyarbakir grand mosque

Auditory perception, which is defined as the conscious and unconscious perception of sound signals, causes different interpretations of the acoustic environment by users. Addressing the quality of the sound environment in the space not only with internationally valid objective methods but also in terms of user perception offers a more holistic evaluation opportunity. The concept of soundscape, which is defined as the acoustic environment that is perceived, experienced and/or understood by people in a context, deals with the sound environment in this context. In this approach, sound can be evaluated as a resource and the effects of these resources on the user in different contexts can be examined. Thus, different from the noise policies, evaluations can be made on the basis of the sound source, by reducing/removing the unwanted sounds in the environment and making the preferred sounds more audible. The first examples of soundscape studies were carried out in open spaces, and the ISO 12913 standard allows the studies in this area to be carried out systematically. With the widespread use of indoor studies in recent years, a standard need has arisen for data collection and analysis methods for these spaces. In this direction, studies have been carried out on the usability of the methods used in open spaces, as well as indoors. It is seen that the assessments of the soundscape in indoor spaces are generally within the scope of room acoustics, and soundscape assessments have become widespread in recent years. In this study, qualitative (questionnaire, guided interview and semantic difference test) and quantitative (binaural sound recordings) soundscape data collection methods used in open spaces; aimed to examine its usability in semi-open and indoor spaces. Since it contains open, semi-open and interior spaces, spaces of worship have been determined as study areas, and it has been determined that soundscape studies related to these structures are not as common as room acoustic studies. Forming the Diyarbakir Great Mosque complex, one of the spaces of worship; Qualitative and quantitative data were collected in open (square), semi-open (courtyard) and interior (Hanefiler Section, Shafis Section and Western Maksure). In order to collect qualitative data, questionnaire, guided interview and semantic difference test forms prepared with reference to ISO 12913-2:2018 standard and soundscape studies were applied to the participants. With the guided interviews, the soundscape perceptions of the participants about the space were examined in more detail, and in the semantic difference test, the subjective interpretation of the soundscape was evaluated with 24 adjective pairs. By analyzing the binaural sound recordings made in spaces in the laboratory, sound level (LeqA, L5, L95) and sound quality metrics which are loudness (N5, N50, N95), sharpness (S5, S50, S95), roughness (R10, R50), fluctation strength (F10, F50) measurements statistical values were calculated with reference to ISO 12913-3:2019. The usability of the soundscape evaluation methods used in open spaces, also in semi-open and indoor spaces, has been verified by associating the obtained qualitative and quantitative data with statistical analysis. It shows that the sound quality metrics of the sharpness in the open space and the fluctation strength in the indoor space can be done through sound quality metrics other than the user, in the soundscape studies that are perceived as positive. It was found that the soundscape assessment was positively related to the suitability of environmental sounds for the open, semi-open, indoor category. It has been found that the perceived auditory quality differs according to demographic factors (age, gender, education), frequency of visiting the space and duration of stay in the space. It has been determined that the relationship between the semantic difference test and sound quality metrics is different for open, semi-open and indoor spaces. Solution suggestions are presented for disturbing sound sources in spaces with defined soundscape. It is thought that making the inactive ornamental pool operational in the courtyard and closing the Gazi Street in front of the square to the vehicle entrance may reduce these disturbances. In order to reduce the discomfort heard from children's voices in the interior, it is recommended to make a special area for children in the portico section on the lower floor of the West Maksure near the entrance of the Şafiler Section. It is predicted that the increase in the Qur'an recital and mystical sounds, which are among the preferred sound sources in the spaces, will reflect positively on the soundscape.