2.5 Acoustic Design for an Auditorium 2.5.1
Selection of the site The proposed site for the auditorium should be as far away as possible from noisy places, like railway tracks, roads with heavy traffic, airports, and industrial vicinities.
2.5.2
Volume The size of the auditorium should remain optimum: small halls leads to irregular distribution of sound because of the formation of standing waves. On the other hand, overly large halls create a weaker intensity and longer reverberation time which may result in serious hearing issues.
2.5.3
Shape and Form One of the most important parameters to be considered for an acoustically efficient auditorium design is the shape and form. Reflections are mainly created due to the presence of side walls and roof of the auditorium; thus, great planning is a must to ensure the reduction of echoes. In the case of parallel walls, splayed side walls are preferred. Curved surface on walls, ceilings or floors are also ideal when the aim is to produce a concentration of sound in a specific region.
2.5.4
Use of Absorbents When the construction of an auditorium is completed; there are still certain inaccuracies that require further improvements to achieve a better acoustical design. Hence, the use of absorbents is essential and a common strategy in amphitheatre design. They are often used at the rear wall of the amphitheatre, as well as the ceiling, as the reflection sound that occurs around these areas are of no benefit.
2.5.5
Reverberation Reverberation time must be controlled to be a perfect balance (e.g. 0.5 seconds for auditoriums, 1.2 seconds for concert hall and 2 seconds for theatres). The proper use of absorbent materials, the capacity of audience, presence of open windows, types of furniture used, are all examples of important components that affect the reverberation time.
2.5.6
Echelon Effect In an auditorium, any set of hand railings, staircases or any regular spacing of reflected surfaces may produce a musical note due to regular succession of echoes of the original sound. This disturbs the quality of the original sounds produced.
Case study of Connexion@Nexus auditorium
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