Soundscape Model in Shiraz Qajar Gardens

Visual landscape and soundscape have a close relationship with each other and a significant impact on the experience of space users. Ignoring mutual design between soundscape and visual scape in most urban spaces has created places that do not have commensurate beauty and sound desirability with space performance, despite their pleasant visual and physical quality. Additionally, sound pollution in modern cities is increasing day by day, which can greatly affect the mental health of citizens. Given the importance of the subject and concentrating existing qualities in Persian garden, this study tries to find the sound model of Persian gardens (case study: Shiraz Qajar Gardens). It also focuses on finding effective environmental components on soundscape in such gardens to probably obtain appropriate sound models for designing urban parks in similar studies. Therefore, these questions arise: what are the common and effective qualitative and quantitative components of creating the soundscape in Shiraz Qajar Gardens? And how does the people’s perception of the soundscape in Persian garden (Shiraz Qajar Gardens) help us to obtain a soundscape model?

In order to provide sound models of Shiraz Qajar Gardens, a qualitative-quantitative method has been used. Data is analyzed by the factor analysis method. In order to obtain a sound map of specified gardens, TES 1353s audiometer with a range of 30-130 decibels has been considered to achieve Leq in the garden at stations in the distance of 10 meters. The existing decibel rates were measured and analyzed on the map. After sound recording by the audiometer in the range of 30 seconds, the Leq of determined stations by GIS software was drawn on the map.

The results, obtained from sound maps in Shiraz gardens, are as follows:In case of increasing sound intensity and given the garden walls, their different heights, and the type of vegetation around the wall, sound intensity is different in the gardens.Sound intensity undesirably increased in adjacent walls of the street, while the increase in sound intensity was pleasant for humans around the pool.In a farther distance away from the streets around the garden and due to neutralization of a part of the sound by vegetation as well as path motion nature without interruption, sound intensity decreases in main axes, and the sound Leq index is usually similar in all points.Since the interpretation of obtained information through sound extraction is only possible by the adaptation of garden users, to validate the quantitative data and assess its quality, a questionnaire was provided in two mental and physical aspects, named in short psychosomatic. In order to investigate the relationship between mental and physical perception, a correlation test was used. Based on the obtained results, the Pearson correlation coefficient was 0.536, and the significance level 0.000. Since the significance level is less than 0.05, a significant relationship between physical and mental perception is confirmed as a result. Based on qualitative-quantitative analyses, it can be said that the obtained results are similar given the common model in designing a Persian garden in determined stations. In stations adjacent to the garden wall near the main street, in which the contexture has changed from rigid to permeable (fencing), the sound is more intense and inconsistent with the sound model of most Persian gardens. The indexes of sound desirability in the questionnaire include attractiveness, harmony with the environment, similarity with music, revitalization, and satisfaction. Given the obtained results, the recorded sounds in the main axes, near the mansion, near the garden wall, sub-axes, and adjacent to the main pool are more desirable, and the entrance has been described neutrally. Regarding that sound intensity in sub-axes (lower) has been described as relaxing, like the one adjacent to mansion (higher intensity space), the silence is not considered as relaxing criterion, and the impact of space on Persian garden on mind is considered. In the main axis, near the mansion and main pool, visual and sound proportion is the highest range, indicating the conscious design of soundscape in Persian gardens. This proportion is less in sub-axes than the adjacent garden walls due to changing the type of walls and their clarification.

A single pattern that all study gardens have followed has balanced sound intensity by creating space psychosomatic quality. The powerful physical components used in spatial geometry of the middle axis of gardens such as chrysogonum, pools, water axes, continuous tree planting, and creating central view corridor and floor materials create the quality indexes of the garden soundscape. In this study, the significant relationship between such physical components and users’ mental perception was confirmed. Therefore, despite the changing behavioral model and physical components of contemporary urbanization of Iran, such as the streets and the traffic noises, and other contemporary artificial sounds, the sound map of the main axis of Persian garden follows a single sound model, indicating that the ancient model can be still used as a vital solution in urban park design.