Browsing by Subject "Room acoustics"

Now showing 1 - 5 of 5

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Acoustical assessment of music halls with variable systems through objective and subjective methods: the case of Bilkent Music Hall
(2024-07) Altun, Aslı
In concert halls, the need for variable acoustics elements arises from the diverse demands posed by different types of musical performances. Previous research suggests that incorporating passive variable acoustic solutions can effectively adapt acoustical conditions to suit various musical performance needs. This research explores the challenges and potentials associated with passive variable acoustic techniques in symphonic music venues, with a focus on Bilkent Music Hall in Ankara, Türkiye. This venue serves as the main performance space for the Bilkent Symphony Orchestra (BSO) and is one of the earliest examples of variable acoustic systems. Over this case, the impact of the existing variable acoustic system for diverse musical performances such as chamber music, orchestral music, orchestral music with choir and vocal accompaniment, solo recitals, and occasional speech-oriented activities is investigated. The methodology begins with acoustical field measurements to evaluate the existing variable acoustic system at Bilkent Music Hall, which consists of operable wooden doors with fabric backing. This analysis highlights the need to investigate the contribution of interior finishing materials to excessive sound absorption at low frequencies, as one major problem of the hall. As a second step of the methodology, subjective data is collected through questionnaire and online surveys that are administered to BSO members and Bilkent Music Conservatory faculty and students. The analysis offers insights into the musicians’ acoustical experiences and acoustical preferences in relation to the venue. Later, the findings are compared with precedent cases worldwide. The final step of the study is acoustical simulations that is applied first to assess the occupied state of the hall then to evaluate the proposed design intervention for improving the acoustical comfort within the hall for different music performances.
Open Access
The acoustical characteristics of the Kocatepe Mosque in Ankara, Turkey
(Taylor & Francis, 2008) Sü, Z.; Yilmazer, S.
This research investigates the acoustical characteristics of mosques of the classical Ottoman period and the contemporary period. Kocatepe Mosque, the major mosque in Ankara, Turkey, as a case from the contemporary era is a unique combination of 16th century Ottoman aesthetics and 20th century technology. Although previous and recent mosques have been inspired by this combination, the use of a reinforced concrete dome without cavity resonators could cause long reverberation times especially in low frequencies. The purpose of this study was to investigate this condition by studying Kocatepe Mosque. The acoustical characteristics of the mosque were analyzed by computer simulation. Objective room-acoustic indicators including reverberation time (RT), early decay time (EDT), clarity (C80), definition (D50), lateral fraction (LF), speech transmission index (STI) and strength (G) are presented. The results show that the acoustical quality of Kocatepe Mosque is not optimal when it is empty, and closest to optimal conditions when fully occupied. The new techniques to overcome excessive low frequency attenuation caused by huge concrete shells of today's mosques are discussed in conclusion.
Open Access
Assessment of reverberance perception and preferential acoustical conditions in educational atriums
(2022-07) Naeemaee, Rozhin
Atriums, with their large spans and superior voids, in modern life have changed their patterns of use from being only circulation zones to multi-functional gathering spaces. One solution to the challenge of transforming atriums to function as multifunctional spaces is optimizing the reverberation time. However, the optimum criteria of reverberation time for atriums have not yet well been set. This causes unnecessary intent of acoustical material applications within contemporary atriums. This study aims to provide a ground for such discussion on the optimum criteria, which can in the future lead to changes in standards and codes. With an aim of defining a proper range for reverberation per function and volume of the space, this research investigates the perception and preference of reverberation metrics (T30, EDT) within the context of educational atriums. The methodology starts with field tests and field surveys within four atriums of different departments at Bilkent University. Acoustical models of the atriums are tuned according to the field tests. Next, interior surface materials are modified for obtaining different sound energy decay rates and auralizations are applied to be used in subjective testing to seek preferential listening conditions. Produced audio clips by auralizations reflect different reverberation settings by the systemically increased amount of absorption, which is grouped for different intervals. An online listening test and questionnaire are held over a sample group of 67 students. Based on the analysis, the audio clips from groups G2 (1.00 s
Open Access
Diffusion equation modeling for sound energy flow analysis in multi domain structures
(Acoustical Society of America, 2019) Gül, Zühre Sü; Odabaş, E.; Xiang, N.; Çalışkan, M.
This study investigates reliable models and methods to be applied in sound field analysis of multi-domain structures. The case structures are two monuments, namely, Süleymaniye Mosque and Hagia Sophia in İstanbul. These are both multi-volume spaces with many smaller sub-volumes coupled to each other by coupling apertures in form of arches. A key concern of the study is to examine energy flow decays and understand the mechanism of multi-slope sound energy decays. The methodology involves diffusion equation model (DEM) application in a finite-element scheme for sound energy flow analysis. Energy flow decays, energy flow dips, and spatial flow vectors are examined for single versus multi-domain DEM solutions. It is concluded that specification of different domains with individual diffusion coefficients is a critical setting such that, if not assigned correctly, may mislead the results. The energy flow vector analysis has enabled us to comprehend the architectural features in relation to such energy flow decay dip occurrence. The computational efficiency of DEM is also discussed. The DEM application in this study has proved to be a powerful and practical method in room acoustics applications, specifically for multi-rate decay investigations.
Open Access
Effects of perceived singing effort on classical singers’ reverberation time preferences towards music practice rooms
(Elsevier, 2018) Sinal, Özgün; Yılmazer, Semiha
The purpose of this study is to investigate the effect of perceived singing effort on classical singers’ reverberation time preferences in individual music practice rooms. The method has combined objective measurements (RT) and perceptual responses of participants. The participant group [N = 30] has consisted of five different backgrounds in vocal studies; early music education (EME) students, skilled amateurs, undergraduate singing students, graduate singing students, and professionals. Classical singers has been asked to sing with as high and as low as they could with melisma singing style (in opera singing technique) in three different room settings which had following reverberation times; around 0.6 s, 0.8 s, and 1.0 s. These were the values, which acoustical standards for music schools recommended. The participants have also been asked to sing with three different singing volumes in each room setting. The findings have been analysed statistically. The results showed that classical singers have preferred the room setting with 0.8 s reverberation time considering their overall experience in these room settings. Classical singers’ perceived singing effort had a statistically significant relationship with preferred room setting. Furthermore, it has been found that there is a relationship between preference and background in vocal studies.