Purpose of this study is to generate Sound Quality Index (SQI) in order to estimate pleasantness of users with sound environment in urban spaces by employing sound quality metrics together such as loudness, sharpness and roughness, which are frequently stated in soundscape studies as it is directly related to human perception. For this purpose, binaural sound records have been conducted and quantitative data of loudness, sharpness and roughness of these metrics of the sound records has been calculated. 27 sound clips, containing different quantitative data of each of the three metrics, have been generated by picking them out of binaural sound records. Participants have listened to the sound clips at laboratory environment, and have been applied jury test. Correlations between pleasantness of users with sound environment and sound quality metrics have been determined by analyzing results from jury test and quantitative data of sound clips. SQI has been generated with a correlation model by using Regression Analysis method. In order to check the accuracy of the model, surveys have been conducted on users at the field and binaural sound records have been taken simultaneously to the surveys. Quantitative data obtained from sound records has been calculated by SQI, and pleasantness level of users with sound environment has been estimated. Results obtained from surveys conducted at the field and results estimated by SQI have been compared. Apart from quantitative data of sound records, effect of parameters that might affect pleasantness of users with sound environment in urban spaces has been determined.

In this study, the aircraft noise near airports at a range of 1-mile propagation has been investigated and the corresponding sound pressure level has been computed. Due to the meteorological conditions, the acoustic impedance of ground and various wave propagation phenomena, the attenuation of sound level propagated from source to receiver, has been calculated [G. J. Ruijgrok, J. Sound Vib. 72(4), 469–479 (1980)]. Also, during the temperature lapse and inversion, the boundaries of upwind zone and downwind zone (acoustic shadow and light zones) have been determined [F. M. Wiener and D. N. Keast, J. Acoust. Soc. Am. 31, 724–733 (1959)]. Accordingly, the residential areas have been established within the boundary of shadow zone in which sound is not absorbed, while the light zone has been used for certain purposes. Further, the heights of residential buildings in the shadow zone have been found according to the rays of sound waves which propagate respectively upward and downward during the temperature lapse and inversion; this will aid architects in design layout and in decision concerning the exterior construction of buildings. [Work supported by the Ministry of Public Works.]

Noise may impair childhood development and education, which may have lifelong effects on academic achievement and health. Children are known to be exposed to unhealthy levels of noise at home and at school. Long term exposure to environmental noise, especially to airport noise, in schools, effect attention, comprehension, recall and recognition skills. Acute noise exposure was found to effect recall and recognition in students. Irrelevant speech, even in an unfamiliar language, interferes with serial recall skills and causes attentional distraction.Although the studies on noise exposure of children are executed in schools, home learning environment should provide auditory comfort conditions for homework performance. In this study, the effect of various sound environments on homework performance was investigated through the duration and correctness of solving algebraic equations in multiple choice tests. High school students (17-18 years, N=32) solved quadratic equations listening to sound clips (L Aeq =55 dBA): quiet (no sound), aircraft takeoff sound, continuous road traffic sound, verbal television sound, a music piece and children playing (talking, screaming, running).Statistically, aircraft, verbal and children sounds effected homework performance, road traffic and music piece did not. Playing children sounds, which include speech, screaming and running, had a more impairing effect than speech from television, even though they had the same equivalent sound level. Participants' self-reported activity disturbance was dependent on the duration to solve the algebraic equations. The study shows the importance of sound insulation against airport noise, neighbor noise and even noise inside the home, for the academic performance of children.

The future traffic noise generation from Trans-European Motorways still under construction throughout Europe was analyzed in a study aimed to introduce standard noise control systems into the TEM Recommendations. Different prediction techniques developed by national institutions of nine countries were employed in computations of noise levels at 15 m from curbsides for varying traffic parameters. Comparisons between results relative to the procedures demonstrated that the USA method (FHWA) yielded about 5 dBA higher levels than European models especially in mountainous terrains and at higher percentages of heavy vehicles. Applying a statistical regression analysis, a simplified mathematical model for TEM noise predictions was developed with a satisfactory correlation coefficient. A new combined parameter, T(u,s,n,h,g), corresponding to interrelated TEM traffic variables (volume, speed, number of lanes, heavy vehicle percentage, and road gradient), affecting noise generation, was analytically defined and represented in the model. Reviewing the existing traffic noise criteria in the world and TEM countries, the prediction model was then improved to establish TEM noise standards taking into account environmental factors and was implemented for the required performances of the noise abatement measures applicable in every type of TEM. [Supported by Directorate of Turkish Highways within the TEM project coordinated by United Nations, Transport Division.]

In this study, it was aimed to measure the perception of sound environment of users in urban spaces with sound quality metrics (loudness, sharpness, roughness, and fluctuation strength). For this purpose, a questionnaire was applied to participants in Gazi Street, Suriçi district of Diyarbakir, which was selected as a field study. In the questionnaire study, participants were asked about the demographic / personal characteristics, questions about the purpose and duration of use of the space, and 35 adjective pairs with 5 bipolar scales in order to determine the perception of the sound environment. Binaural sound recordings were also performed simultaneously when the survey was conducted. The quantitative data of the loudness, sharpness, roughness, and fluctuation strength metrics of these sound records are calculated. By analyzing the results obtained from the questionnaire and the quantitative data of the sound recordings, correlations between the sound environment perception of the users and the sound quality metrics were determined. Apart from the quantitative data of sound recordings, the effect of the parameters (demographic / personal / social) which can affect the perception of the sound environment in urban spaces has been tried to be determined. In addition, the relationship between quantitative data of sound recordings and meteorological data has also been analyzed.