Choir’s “Alien” Feeling Aids Concert-Hall Design
In Anechoic Space, No One Can Hear You Sing. An eighty-voice college choir was closed inside an anechoic research chamber, a space designed and built to eliminate all echoes and sound reflections.
For the singers, the environment was eerily quiet – a quiet softer than anything they experience in everyday life. Several choir members, feeling claustrophobic, had to leave. In a normal rehearsal or concert space, each singer can hear the group’s unified sound reflected back from the walls and ceiling. However, all interior surfaces in this chamber are covered with sound-absorptive fiberglass wedges, intended to prevent any reflections. It measures 25’ (7.6 m) wide, by 30’ (9.1 m) long, by 20’ (6.1 m) high.
Organized by Wenger, this performance by a choir from St. Olaf College in Northfield, Minn., took place at a 3M research facility in St. Paul, Minn. It was an unqualified success, resulting in an anechoic choral recording – “pure” sound – for use in a type of acoustical research called auralization.
Developing a Performing Hall’s ‘Signature’. Auralization software helps acoustical consultants predict – and modify – how a proposed performance space, like a concert hall, will sound while still in the design stages. The software considers the room size and shape, along with the acoustical properties of all surfaces, and applies these combined parameters to an anechoic recording such as the reflection-free sound of this choral recording. The result is the auralization or acoustical ‘signature’ of the new space.
Free Resource for Architects, Acousticians. “Wenger spearheaded this recording project to help advance research in the field of architectural acoustics,” says Ron Freiheit, Director of Design Engineering with Wenger and a Fellow of the Acoustical Society of America (ASA).
During new construction and renovation projects, Wenger works closely with architects, acoustical consultants and other design professionals to help create superior acoustical environments, ranging from performing arts centers to school rehearsal facilities.
Freiheit also used auralization software and this anechoic choral recording to demonstrate the ‘before/after’ impact of acoustical treatment in a performance hall – including acoustical shell towers, ceiling panels and acoustical clouds.
The anechoic CD/DVD recordings have been provided at no charge to research groups, institutions and consultants around the world. To request your free copy, contact Freiheit at 1-800-326-8373, ext. 139, or via e-mail at firstname.lastname@example.org.