Echo chamber

Sacred music of the Medieval and Renaissance periods relied heavily on the composers' extensive understanding and use of the complex natural reverberation and echoes inside churches and cathedrals.

Architects designed these to create internal reflections that would enhance and project sound from the stage in the days before electrical amplification.

[citation needed] Developments in electronics in the early 20th century—specifically the invention of the amplifier and the microphone—led to the creation of the first artificial echo chambers, built for radio and recording studios.

The basic purpose of such chambers is to add colour and depth to the original sound, and to simulate the rich natural reverberation that is a feature of large concert halls.

Consequently, record producers and engineers quickly came up with an effective method of adding "artificial" echo and reverberation that experts could control with a remarkable degree of accuracy.

The original echo chamber at EMI's Abbey Road Studios was improved by Clive Robinson, site foreman at the time of construction.

It was one of the first studios in the world to be specially built for recording purposes when it was established in 1931; it remains in place and is a prime example of the early 20th-century electro-acoustic echo chamber.

Famous examples include Sir George Martin's AIR Studios at Lyndhurst Hall in Belsize Park, London, a large, vaulted 19th-century building originally constructed as a church and missionary school.

In the 1950s and 1960s, the development of magnetic audio tape technology made it possible to duplicate physical echo and reverberation effects entirely electronically.

The actual length of the delay between each repeat can be varied by a pitch control that alters the speed of the tape loop across the heads.

However, as noted above, naturally reverberant spaces such as churches continue to be used as recording venues for classical and other forms of acoustic music.