Browsing by Subject "noise annoyance"

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Open Access
Acoustical comfort evaluation in enclosed public spaces with a central atrium : a case study in food court of CEPA Shopping Center, Ankara
(2009) Dökmeci, Papatya Nur
Physical comfort requirements of users as thermal, visual, and acoustic comfort should be considered and studied in detail when designing and planning public spaces. The subjective auditory perception needs to be evaluated parallel with the objective acoustical incidences in a space. The food court area of CEPA Shopping Center with an atrium and a glass dome ceiling, in the capital city of Turkey, Ankara is chosen for the case. The aim of this study is to investigate acoustical parameters of the space via computer simulation program and examine the effect of architectural features of the space namely; central atrium, glass dome and the existing material applications. Considering the relationship between the users’ noise annoyance and the equivalent continuous sound pressure level (Leq) is also intended in this study. The research techniques are computer simulations, noise measurements and questionnaires. Acoustical parameters; reverberation time (RT), early decay time (EDT), sound transmission index (STI) and equivalent continuous sound pressure level (Leq) values are obtained by simulations and measurements. Questionnaires are used for understanding the noise annoyance and auditory perception of the users. The results show that the noise annoyance ratings correlate well with the Leq variances. The most dominantly perceived and the most annoying sound found to be correlated with the highest percentage for speech noise in the food court. Decay time (T30, EDT) results of the space that are derived from the ODEON 6.5 software are found to be very long as expected with a central atrium, glass dome ceiling and highly reflected material applications. In addition, the food court area is defined to be poor in terms of STI. High Leq values as well as long decay times that are present in the space are noted as factors increasing the noise annoyance of the users.
Open Access
Understanding soundscape in public spaces : a case study in Akköprü Metro Station, Ankara
(2014) Bora, Zeynep
In 2008, a working group of ISO/TC 43/SCI/WG 54 “Perceptual Assessment of Soundscape Quality of the International Organization for Standardization” was established and they published the first part of standardization “ISO 12913-1 Acoustics-Soundscape-Definition and conceptual framework” In their framework the acoustic environment divides into two main categories according to places; indoor and outdoor acoustic environment. The working group ISO/TC 43/SCI/WG 54 is being to standardize the methods and parameters of soundscape quality outdoors and point out both the negative and positive aspects of sounds environment as perceived by people. Besides the soundscape quality outdoors, indoors are also needed to be studying in the field. This study has been designed to understand the indoor acoustic environment of the metro station which is chosen as a public space. Aim of this study is to find out both negative and positive aspects of indoor acoustic environment as perceived by users in metro station. In order to compare outdoor and indoor soundscape qualities, Akköprü Metro Station and its immediate surrounding were chosen as a case study in Ankara, Turkey. The park shared the same environment with metro station was chosen as an outdoor environment/open public space. Entrance of the metro station was chosen as a semi open public space and the platform of the metro station was chosen as an indoor environment/enclosed public space. Within “a degree of enclosure” context, objective, subjective and psychoacoustics parameters for soundscape quality were measured in three spaces. As objective parameters, A-Weighted Equivalent Continuous Sound Levels (LeqA), Sound Pressure Levels" (SPL), Reverberation Time (RT), Speech Transmission Index (STI) were measured. For subjective parameters, sound recordings were taken with soundwalk method and noise annoyance surveys were applied simultaneously. A listening test and a survey were prepared to understand if spaces could be recognized/understood just by hearing. For psychoacoustics parameters, questionnaires were prepared and subjects were asked to fill in personal information and for each sound recording they listen, they were asked to fill in four open ended questions and choose from seventeen adjective pairs prepared with one to five likert scale. Ninety applicants participated in a listening test. Results showed that, acoustical measurements were higher than the permissible limits given in regulations. According to the noise annoyance survey results, enclosed spaces have the highest noise annoyance rating. Demographic factors such as age, gender, education level and space recognition did not showed any significant correlation. According to the listening test results, 70% of the subjects were able to determine spaces correctly as open, semi open or enclosed. Only 55% of the subjects were able to recognize the spaces. Soundmarks of the spaces show similarities. In open spaces subjects tended to choose adjectives such as "pleasant", "calming", "natural", "joyful"; while in enclosed spaces they tended to choose adjectives such as "unpleasant", "stressing", "artificial" , "empty".