Acoustical assessment of music halls with variable systems through objective and subjective methods: the case of Bilkent Music Hall

Abstract

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.