Urban soundscape research in the route of Gezi Parkı-Tunel Square

The idea of soundscape was released on the second half of the 20th century and since then there have been done several big projects and research all around the world about soundscapes and its effects. Soundscape was described firstly by R. Murray Schafer – a Canadian composer; the term of 'soundscape' refers into the whole sounds in an area, a place or a region. Research subjects of the soundscape studies include the all sounds in the research fields and the effects of the sound environment on the human perception with regards to the factors about psychological, sociological, demographical, ethnical etc. By taking into consideration of these issues it can be said that every soundscape project or research is special to its field. However, there are still common features about the soundscapes and the evaluation methods which are accepted universally. Even so soundscape studies and methodologies always have potential to develop and change. Bringing forward the idea of soundscape is usually connected to the concept of noise evaluation which may differ subjectively; some sounds or sound environments, which are described as noisy physically, are not always perceived negative: These are sometimes perceived positive and even comfortable by people. On the contrary sounds in low levels or sound environments which are not proper for the physical noise description may be percevied as negative and disturbing. As a matter of course this situation is not convenient for too high sound pressure levels (above 70 – 75 dB are generally accepted as too high). The important fact of this way of thinking is that the human perception of sound environment depends on not only the objective parameters but also the subjective evaluations strongly. Because of these reasons, noise descriptions change according to the subjective parameters and become special for each place, area or region. There is a common example about train stations which is given to be able to understand the soundscape idea. According to this example, when a person is waiting for a person he / she likes, the sound of the train that draws in the station is not percevied noisy by him / her; the opposite way round, this sound can make him / her happy. In a similar manner, for example the sizzle of an electronic device may be annoying even though the sound level is too low. There are a lot of examples which have the same or similar logic to understand or describe the soundscapes. By using the concept of soundscape, it is possible to evaluate urban sound environment as well. When the soundscape idea is adapted to urban scale, it is seen that different parts of the cities have distinctive soundscapes which constitute a significant part of the city identity. It is important to find out the soundscape characteristics of a city or a region since it is required to be able to increase the acoustic comfort in the city and to save or to change the sound environment properly where necessary. There have been a lot of urban soundscape research worldwide and most of the metropolitans have been evaluated from the point of soundscape by this way. In this thesis study a soundscape research has been designed and applied with some practices in the route between Gezi Park and Tünel Square. The main method that the study depends on is soundwalk method. Soundwalks are applied on the research field by walking along the route silently and after the walk the questions about the soundscape characteristics of the route and its perceptual features are answered by the participants. Before the thesis study was started, two pilot studies were done by applying two different soundwalk methods. In the first pilot study the soundwalk method that was used in the Positive Soundscape Project was performed. Positive Soundscape Project (PSP) was conducted in England, and its soundwalk method was derived from Schafer's Method (this one is the method of the second pilot study). According to PSP's method the participants walk along the route silently, they stop only in some previously determined key locations and answer the questions about the sound environment of the key locations. For the route of Gezi Park – Tünel Square, four key locations were determined as Gezi Park, Taksim Square, Galatasaray Square and Tünel Square; however this method lasted a long time and the participants were unable to concentrate on the sounds towards the end of the walk. As it is mentiond before, in the second pilot study Schafer's method which was applied during the World Soundscape Project (WSP) by Schafer was performed. The participants walked along the route nonstop and silently, at the end of the walk they answered the questions about the soundscape characteristics. Schafer's method was more comfortable for the participants because it took less time in compare with previous and they did not lose their attention during the soundwalk. Nevertheless this method was disapproved for the study since there are some important transition points which refer to the diversities of physical properties and the sound environments on the route, and it is not efficient to obtain information about them by this way. For the above-mentioned reasons, a combination of these two methods was built and applied. First of all the four key locations were kept as Gezi Park, Taksim Square, Galatasaray Square and Tünel Square. The participants were started to soundwalk from Gezi Park subway exit, walked through the park and stopped before the stairs going down to Taksim Square. For each key location, a point was determined to stop; for Taksim Square the point is between the monument and the enter of İstiklal Street, for Galatasaray Square it is after Galatasaray High School and for Tünel Square it is in the middle of the square. The participants were stopped at these points and filled five different tables for each key location; they maintained the silence even during the stops. Three of the tables contain some words which help to define the soundscape characteristics of each key location with regard to technical issues, by using mimetic words and descriptors for feelings, respectively. The other tables are for subjective evaluation of loudness and acoustic comfort evaluation. The participants were asked to put only signs for each key location and the process was lasted about five minutes at each stop. At the end of the soundwalk, two questionnaires which were given for evaluation of the soundscape(s) of the whole route were filled out by the participants. The first questionnaire form involves questions about sound sources and their effects on the soundscape in general. Additionally it has two tables – one for determination of efficiency rate and the other one for positiveness rate of sound sources; and two more tables for subjective evaluation of loudness and acoustic comfort evalution of the whole route. The second questionnaire contains questions about the number of the percevied soundscape and classification of them. By this way it was aimed to determine the soundscape(s) of the route and to evaluate the effects of the key locations on the classification of the soundscape(s). Apart from the soundwalks, 10 sound recordings were made on the route by using a sound level meter. When the key locations are taken into consideration it can be thought that the soundwalk consists of four parts; therefore these four parts of the soundwalk were recorded and also four more recordings were made at each key location by stopping at each one stretching 5 minutes. Besides two more sound recordings were made by walking nonstop the whole route, one is from beginning to end (from Gezi Park to Tünel Square) and the other one is from end to beginning. By using these 10 sound recordings, post – signal analysis were done and values of sound pressure level, roughness, loudness and sharpness were measured for each recording. Since the number of the recordings – measurements remained low, the statistical analysis was not thought reliable; but within the scope of the thesis the results of the measurements for four soundwalk parts are given to have an idea and to be able to make comparisons between them. That is to say the results of 5 of the recordings (four soundwalk parts and one the whole route from beginninng to end) took place in the thesis. Besides these, a quite wide literature review is given at the lead of the thesis. Academic publishings, conducted projects and written books about the soundscape were investigated as far as possible. Literature review was collected under four titles: First one is about World Soundscape Project and the second one is about Positive Soundscape Project. These two titles were created because of the fact that the soundwalk method that was applied during the thesis study was constituted by being inspired from these projects and also each project is one of the most comprehensive projects. The third title under the literature review investigates the other important projects, academic research, etc. The soundscape studies which have been done in Turkey is given under the fourth title. 50 participants joined to the soundwalks and important results were obtained during the thesis study. Almost all of the participants are university students or graduated from university. Most of them are at the age of between 19 – 30. As it is expected the most well-known sound of the route, in other words the symbol sound, or the sound that comes to mind when it is mentioned about Taksim Square – İstiklal Street is tram. Sounds of street artists (musicians), street vendors etc. are also the most expected sounds according to the results from questionaires which were filled before soundwalks. The tables that were given to the participants to describe the sound environment at each key location have shown that Gezi Park comes to prominent as positive compare to the other key locations. Tunel Square follows Gezi Park with regard to the descriptors (technical, feelings) – words (mimetic). Galatasaray Square and Tünel Square are generally percevied as negative and the sound environmet of these two key locations are seen as annoying. These results are supported with the results of the subjective evaluation of loudness and acoustic comfort evaluation which were filled again at each key location. Galatasaray and Taksim have come to the picture as the most noisy and discomfortable locations on the route. On the other hand, comparatively the most silent and comfortable locations have been Gezi and Tünel. It is important to point out that here Gezi Park refers to the not only the determined stop point on the park but also to the soundwalk route through the park; and for other three key locations the situation is similar; Taksim Square refers to the place of the soundwalk part between the end of the Gezi Park and the beginning of İstiklal Street, Galatasaray Square refers to the first part of the İstiklal Street – from the beginning of the street to Galatasaray, and Tünel Square refers to the second part of the street from Galatasaray to Tünel. Since the number of the sound recordings were quite low, the measurement results were not used for statistical analysis. It was tried to obtain some statistical correlations, however these are not presented in the context of the thesis since they are not condsidered reliable enough. Nonetheless when comparisons have been made between the measurements of key locations, some interesting results have been obtained. Even though the most silent location is Gezi Park according to the subjective evaluation of loudness, it is seen form measurements that the sound pressure level of Taksim Square is lower than Gezi Park. Similarly Tünel Square has the highest sound pressure level with Galatasaray Square, but Taksim perceived more noisy than Tünel with regards to subjective evaluation of loudness. This circumstance may be attributed to the starting point of the soundscape idea. In addition to these roughness values of the key locations show parallelism with results of subjective evaluation of loudness and acoustic comfort evaluation, however again because of the low number of measurements these are not presented. The findings from the questionaires which were answered after soundwalks indicate that street artists (musicians), rubbish / cleaning cars and street vendors are the sound sources which have the maximum effect on the soundscape of the route. The effect of tram gets behind in as against to street artists. The most positive sounds are sourced from street artists, birds and water. Especially sounds of birds and water are monitored in Gezi Park and these different sound sources make the soundscape of the park unique with compare to the other key locations. The effecting rate and positiveness rate of tram are lower from expectations; and the values are just in average. The questions of 'How many soundscapes did you perceive?' and 'How would you classify the soundscape(s) of the route?' are seen as the key aspects for thesis. The results presented in the thesis are aimed to guide to these questions. According to their answers the participants come under two main groups. The participants in the first main group remarked that they had perceived two soundscapes along the route; one of them is Gezi and the other one is the whole of Taksim – Galatasaray – Tünel. The second main group is splitted up two subgroups: One of the subgroups indicated that there were three soundscapes on the route; first one is Gezi, the other one is Taksim – Galatasaray and the last one is Tünel. The participants of the other subgroup were stated that there were four soundscapes on the route, perceptively. According to their point of view, each key location represent a different soundscape, which means Gezi Park, Taksim Square, Galatasaray Square and Tünel Square correspond to distinctive soundscape, respectively. The essential difference between the main groups is the thought about Tünel Square. It is seen as the most important point of the thesis study. Indeed there is almost no difference between physical characteristics and architectural features of Galatasaray and Tünel, however these main groups disaccord of the soundscape of Tünel whether it is in a unity with Galatasaray or not. The numbers of the participants who distinguish Galatasaray and Tünel and who do not, are almost in half shares. After this significant finding, the reasons for this situation were investigated and the results which have been obtained thus far are connected to this result. It is titled as 'synthesizing of general findings' and take place at the last parts of the thesis with a detailed graphical presentation. Galatasaray and Tünel are two main parts of the whole Istiklal Street; Galatasaray is in the middle of the street and Tünel is at the end. Even though the physical differences between them are not so big, they should be taken into consideration. In the first part of Istiklal Street or in other words in Galatasaray part there are more traffic intersections than the second part – Tünel part and this makes the first part more disturbing. Another observable variable is that people density which decreases seriously after Galatasaray Square and through Tünel Square. Nevertheless these differences are the general features of the street and so these can not be the only reasons for seperation of the soundscapes with a sharp contrast. Since there is no apparent and permanent variation between Galatasaray and Tünel, the reasons for seperation were searched in sound sources. Especially street artists (musicians) which are the most effective and positive sound sources on the route, usually perform on the second part of Istiklal Street – after Galatasaray Square until Tünel Square. If the results of the soundwalks which were done when the street artists spread over the whole Istiklal Street, it can be seen that the sound environments of Taksim, Galatasaray and Tünel were percevied as an entire soundscape. As it is mentioned before, tram has had worse performance with regards to effectiveness rate and positiveness rate. When all of these findings are taken into consideration, the conclusion is stated by this means: The sound sources which are spreaded over the street like tram and sometimes street artists, they lose their effects on the soundscape; on the contrary if the sound source is special to a part of the street it becomes more effective on the soundscape and the classification of soundscapes on the route changes correspondingly to effectiveness rate and positiveness rate of the these sound sources. For generalisation of the conclusion, it is necessary to enlarge the research on this route and to do more studies at different places – regions and even cities. The studies may be prepared appropriately for semtinizing the conclusion. Within the scope of the thesis study, this result is represented as special to the route of Gezi Park – Tünel Square; however it has more potential to be referred in a wider scale. The soundscape researc on this route should be expanded as far as possible by thinking the historical, cultural and social importance of the route for Istanbul. After that the research may be spread over the important regions of the city. At this point the findings and results of the thesis study which have been conducted from April 2014 to June 2015 on the route of Gezi Park – Tünel Square, are expected to be starting point and reference guide for future studies that will be done on this route or on another routes through the city. In addition to this, the thesis is expected to provide historical data again for future studies and by this way it will make the comparions in the future possible.