The Anechoic Chamber (anechoic meaning echo-free) is a specialist facility that has been carefully designed and built to achieve almost perfect quiet conditions. Within the chamber, external sound is not allowed to break in and sound reflections off internal room boundaries cannot occur.

Almost perfect acoustic isolation is achieved by a "box in a box" construction made of very heavy concrete walls  and internal surfaces  made of 70cm long foam wedges and large, heavy sound-proof doors. The inner box is mounted on springs to avoid the transmission of vibration from London Underground trains which run underneath the chamber. The suspended floor is made from a metal grill so that heavier equipment, up to 50kg, can be measured. This chamber allows sound power levels to be accurately determined, frequency responses to be measured and pure recordings to be made. Recordings can later be processed to create aural simulations of virtual environments.