An anechoic chamber is a room designed to stop reflections or echoes of either sound or electromagnetic waves. They are also often isolated from energy entering from their surroundings. This combination means that a person or detector exclusively hears direct sounds, in effect simulating being outside in a free field.

Leo Leroy Beranek was an American acoustics expert, former MIT professor, and a founder and former president of Bolt, Beranek and Newman. He authored Acoustics, considered a classic textbook in this field, and its updated and extended version published in 2012 under the title Acoustics: Sound Fields and Transducers. He was also an expert in the design and evaluation of concert halls and opera houses, and authored the classic textbook Music, Acoustics, and Architecture, revised and extended in 2004 under the title Concert Halls and Opera Houses: Music, Acoustics, and Architecture.