Browsing by Author "Saher, Konca"

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Acoustic Assessment of Four Music Rehearsal Rooms in Accordance With ISO23591 Standard
(Elsevier Sci Ltd, 2025) Saher, Konca; Ozgencil, Yalin; Khoshkholghi, Solmaz
Optimizing rehearsal room acoustics is crucial for musicians to perceive sound, pitch, and frequency variations. Since the introduction of the international standard ISO 23591 Acoustic quality criteria for music rehearsal rooms and spaces, research in the field of music rehearsal rooms has significantly intensified. However, relatively few have adopted an approach that integrates both objective measurements and subjective user evaluations, particularly in rehearsal rooms for quiet-category instruments. Therefore, this study aimed to assess and improve the acoustical conditions of four Turkish rehearsal rooms for quiet-category instruments using measurements, simulations, and musician surveys. A survey conducted in the first phase revealed that musicians rated the efficiency, satisfaction, and frequency balance of four rehearsal rooms as bad to fair. Efficiency of rehearsals showed a strong correlation with frequency balance (R2 = 0.72 for low-to-mid; R2 = 0.76 for high-to-mid). Strong correlations (R2 = 0.93) were found between calculated and perceived low-to-mid frequency balance, while high-to-mid frequency balance showed weaker correlations (R2 = 0.36), suggesting possible sensitivity to low-frequency issues; though this did not consistently align with user satisfaction, indicating that additional perceptual factors play a role. Acoustic measurements show that existing reverberation time (RTmid) values for all rooms fall outside recommended limits. The measured rehearsal rooms were modeled, calibrated, and 36 acoustic models were developed with three alternative designs to improve acoustics within recommended limits. Then musicians from these rooms assessed 36 acoustic models through listening tests based on auralizations. Listening tests showed a preference for models with RTmid values within the recommended range, aligning subjective and objective assessments. After the RTmid value, effect of low-to-mid frequency balance was important in the choice of rooms for musicians.
Citation - WoS: 2
Citation - Scopus: 4
Assessment of speech intelligibility during different teaching activities in classrooms with and without acoustic treatment
(Elsevier Sci Ltd, 2023) Şaher, Konca; Bulunuz, Mizrap; Kelmendi, Jonida; Nas, Sezin; Interior Architecture and Environmental Design
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.
Dersliklerde Reverberasyon Süresi ve Gürültü-Sinyal Oranının Yetişkinler ve Çocuklarda Kelime Ayırt Etme Oranına Etkisi
(2019) Şaher, Konca; Interior Architecture and Environmental Design
Bu makale, sınıflarda yetişkinler ve çocuklar için reverberasyon süresi değerlerinin, reverberasyon süresinin frekans aralıklarındaki dağılımının ve sinyal-gürültü oranının konuşmanın anlaşılabilirliğine olan etkisini Türkçe fonetik dengeli tek heceli kelime ayırt etme testleriyle belirlemeyi amaçlamaktadır. Öncelikle, her biri 25 öğeden oluşan 2 takım fonetik dengeli tek heceli Türkçe kelime tam yansımasız bir odada kaydedildi. Kayıtların işitselleştirmeleri akustik bir simülasyon yazılımında tipik bir sınıf için 0,8 saniye (500 Hz, 1000 Hz ve 2000 Hz ortalaması), 0,4 saniye (500 Hz, 1000 Hz ve 2000 Hz ortalaması) ve 0,4 saniye (125–4000 Hz) olmak üzere üç farklı reverberasyon süresi ve iki farklı sinyal-gürültü oranı (0 dB ve 15 dB) için geliştirildi. Üç farklı reverberasyon süresi ve iki farklı sinyal-gürültü oranına sahip altı modeldeki işitselleştirmelerden geliştirilen dinleme testleri, normal işitme yeteneğine sahip genç yetişkinlere ve çocuklara dinletildi. Sonuçlar, 0 dB ve 15 dB olarak her iki sinyal-gürültü oranı için reverberasyon süresi 500 Hz, 1000 Hz ve 2000 Hz ortalaması olarak 0,8 saniyeden 0,4 saniyeye düştüğü zaman, konuşmayı ayırt etme yüzdelerinin yetişkinlerde de çocuklarda da arttığını göstermektedir. Ancak 0 dB sinyal-gürültü durumunda reverberasyon süresi 500 Hz, 1000 Hz ve 2000 Hz ortalaması olarak 0,4 saniyeden 125 Hz – 4000 Hz oktav bantlarının her birinde 0,4 saniye civarına düştüğü zaman yetişkinlerin konuşmayı ayırt etme oranında kayde değer bir iyileşme olmazken, çocukların kelime ayırt etme oranlarının önemli derecede arttığı gözlemlenmiştir. 15 dB sinyal-gürültü oranı için ise 125 Hz – 4000 Hz oktav bantlarının her birinde 0,4 saniye elde edildiği durumun yetişkinlerde de çocuklarda da konuşma anlaşılabilirliğine önemli bir etkisi görülmemektedir.