Browsing by Author "Nas, Sezin"

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Citation - WoS: 4
Citation - Scopus: 5
Assessment of speech intelligibility during different teaching activities in classrooms with and without acoustic treatment
(Elsevier Sci Ltd, 2023) Saher, Konca; Bulunuz, Mizrap; Kelmendi, Jonida; Nas, Sezin
There is limited data for assessing speech intelligibility in real classrooms with realistic occupied noise levels and teacher's and students' speech levels for different teaching activities in Turkish secondary school classrooms. This study investigates the effect of reverberation time (RT), occupied noise levels and signal-to-noise ratio (SNR) on speech transmission index (STI) in real classrooms for instruction and group work. Noise levels were measured and STI values were calculated in two secondary school classrooms with RT of 0.88 s and 2.73 s. During instruction situation, calculated mean STI values were 0.63 (classroom with acoustic treatment) and 0.29 (classroom without acoustic treatment) for normal voice effort and 0.65 (classroom with acoustic treatment) and 0.39 (classroom without acoustic treatment) for raised voice effort. During group work, STI values ranged from 0.50 to 0.74 in classroom with acoustic treatment and from 0.01 to 0.34 in classroom without any acoustic treatment. SNR of 15 dBA is only approached in classroom with acoustic treatment during instruction situation. The effect of increasing SNR on STI is prominent in the classroom without acoustic treatment which already has low SNR values. The present results show that the classroom with acoustic treatment will have good speech intelligibility for instruction with normal vocal effort and for group work with raised vocal effort at 3 m distance. However, the classroom with no acoustic treatment will have STI values in the range of bad and poor intelligibility. The present results confirm the impact of SNR and RT on speech intelligibility and shows that RT value of minimum 0.8 s is optimal to have good speech intelligibility in a secondary school classroom of approximately 250 m3 with a capacity of 18 students.(c) 2023 Elsevier Ltd. All rights reserved.
Exploring the Acoustic Identity of Derinkuyu Underground City
(Int Inst Acoustics & Vibration, 2024) Nas, Sezin; Saher, Konca; Mihci, Giirkan; Aytis, Saadet
Sounds play a significant role in shaping the identity of spaces and places, yet the acoustic environment of underground cities remains relatively unexplored in the existing literature. Derinkuyu Underground City stands as a prominent cultural heritage site, boasting a capacity of 20,000 people and serving as one of the largest underground cities globally. While geological and structural studies have been conducted on such sites, investigations into indoor acoustics, a crucial aspect of the physical environment, are notably lacking. This study initiates an initial examination of the sound environment within Derinkuyu Underground City, aiming to analyse its features acoustically. Undertaking a PhD study, our research endeavours to gather essential data essential for the preservation of the site's current acoustic environment as a cultural heritage site while also generating valuable insights for the design and construction of future underground cities. In this paper, we present a preliminary assessment of the typologies of various spaces within Derinkuyu Underground City, exploring their unique acoustic features. By characterizing and understanding the acoustic properties of diverse spaces within the underground city, we seek to understand how acoustic might contribute to the identity of these spaces and provide foundational knowledge for both preservation efforts and future underground urban design initiatives.
Reflections on the International Noise Awareness Day 2023 Activities
(Int Inst Acoustics & Vibration, 2024) Saher, Konca; Dumen, Ayca Sentop; Sezgin, Hakika; Nas, Sezin; Kelle, Dilara; Demiral, Yacel
This paper presents an overview of the experiences and outcomes derived from the activities organized for International Noise Awareness Day 2023 in Turkey with the theme "Keep your hearing, keep your health". Collaboratively organized by Turkish Acoustical Society, and Occupational Hygienists Society, the initiatives aimed to explore the role of sound in educational facilities, with a particular focus on the perspectives of students and teachers. These activities were a student drawing competition, an online International Symposium, a research project titled "Assessment of Acoustic Conditions in Schools and Health Effects on School," and an "Acoustics Workshop in Educational Buildings" conducted at the Izmir BLX Acoustics Laboratory. Drawing from our experiences and findings, we highlight the significance of actively involving researchers, acoustic consultants, occupational hygienists, teachers, students, and designers in such endeavours. Our findings indicate that inclusive approaches not only boost public engagement but also enhance awareness of behavioural, emotional, educational, administrative and design aspects related to sound. By promoting collaboration and participation in knowledge exchange, such activities significantly improve understanding of sound-related issues in schools.
Citation - Scopus: 1
Room Acoustic Modelling of a Reverberation Chamber
(German Acoustical Society (DEGA), 2016) Şaher, Konca; Nas, Sezin; Karaböce, Baki; Kırbaş, Cafer; Bilgiç, Eyüp
This paper aims at comparing measured broadband reverberation time values in the reverberation chamber of Scientific and Technological Research Council of Turkey - National Metrology Institute (TUBITAK-UME) in Gebze Turkey with the simulated reverberation time values from the room acoustical modelling of the same reverberation chamber. The reverberation chamber in TUBITAK-UME has a volume of 263m3 total inner surface area of 262 m2 and 16 diffusers made of Plexiglas and hung randomly in the room. The majority of the diffusers have hyperbolic shapes. There are also six absorbers to adjust the reverberation time of the room. Indications of difficulties in the calibration of the acoustic model with reference to the measured values and different frequencies are given and the modelling and measurement uncertainties and limitations are discussed. © 2016 German Acoustical Society (DEGA). All rights reserved.