Acoustical quality in concert halls as related to hall shape: Shoebox, surround, and other.

Abstract

(ProQuest: ... denotes formulae omitted)This article examines objective acoustical differences and the spread of acoustical quality among shoebox, nonshoebox, and surround concert This study was motivated by frequent remarks by listeners that there is a greater difference in sound quality depending on the seat locations in nonshoebox halls than in shoebox halls.Here, shoebox halls (SB) are defined as rectangular with the audience seating so configured that large areas of upper sidewalls are available for around-the-hall high-up reverberation (Figure 1a). Parenthetically, in these halls the orchestra is always located at one end. Nonshoebox halls (NSB) are those so configured that at least one sidewall (or rear wall) is mostly covered by audience seating, thus eliminating the possibility of high-up around-the-hall reverberation (Figure 1b). Surround halls (SR) are those in which the audience seating clearly surrounds the orchestra (Figure 1c). The podium is nearer to the center than in traditional SB Typically about half of the audience is seated in several rows that surround the orchestra. In all parts of the hall, the seating is often divided into smaller groups that resemble vineyard steps.The surround-shaped hall originated with the Berlin Philharmonie Hall, in which the architect postulated freer communication between the audience and the musicians (Beranek, 2004, pp. 297-300; Jones, 1989; Lanier, 1964). Also, in most surround halls, around-the-hall high-up reverberation is limited. The different shapes of the halls create variations in several acoustical characteristics which can be heard by experienced listeners. These characteristics include at least: (a) reverberant sound in the upper reaches of a hall, (b) arrival times and number of early lateral reflections, (c) the magnitude of the change in acoustical quality with seat location, and (d) the variation in the balance of sounds between the different sections of the orchestra depending on seat location. Sometimes also cited is Togetherness, the feeling of acoustical intimacy between performers and audience.The shoebox (SB) shape is the geometry that is most likely to be judged as having excellent acoustical quality (Beranek, 1996, Appendix 3; Beranek, 2004, pp. 499-500; Beranek, 2014; Winckel, 1967). The composers of the Classical and Romantic periods of orchestral music created their works largely for performance in SB. Architects and building owners know this but have gone to these other shapes, NSB and SR, largely to create unique architectural designs, and often to decrease the sightline distances between performers and listeners.Meyer (2011) showed that SB and SR halls have been most frequently built after 2000, based on his classification of shapes of 160 concert halls constructed from 1960 to 2010. In relation to the hall shape, he emphasizes the importance of the dynamic balance between the different instrument sections as well as the seating arrangement of orchestra, which he says is very important. He pointed out that for some people architectural innovation seems to be more important than excellent acoustics.After Beranek (personal communication, January 28, 2015), Acoustic Quality is a term often used by acousticians to compare the sound of symphonic music as heard at a seat in a concert hall with that heard at an equivalent seat in the world's older highestrated shoebox-shaped concert halls. This term is also used for opera houses and chamber music halls (Hidaka & Beranek, 2000; Hidaka & Nishihara, 2004; Kahle, 2013). Beranek and one of the authors (Hidaka & Beranek, 2010) also studied the acousticalquality spread from seat to seat relating to the hall shape: shoebox, nonshoebox, and surround. Based on his definition (Beranek, 1996, p. 520) that the acoustical quality of a concert hall is given by a summation i ai|xi|3?2, they compared the degree of variation of the acoustical quality in 18 concert …