An anechoic chamber is also commonly used. In April 2003, an anechoic chamber test facility was established. The NSMRL auditory laboratory includes a large, 1,000 m3 anechoic chamber. It has the only anechoic chamber in the region. It is currently the world's largest anechoic chamber. Professor Balanis is the "architect" of the Arizona State University ElectroMagnetic Anechoic Chamber (EMAC). The "Mind" area contains optical illusions, physical illusions, an anechoic chamber, and a posable zoetrope. A compact range is an anechoic chamber with a reflector to simulate far field conditions. The Murray Hill anechoic chamber, built in 1940, is the world's oldest wedge-based anechoic chamber.