We had been researching the use of pots as acoustic devices in a number of instances throughout history, dating back to accounts of their being integrated into the fabric of Greek amphitheatres. Amongst various sources, Jean-Francois Augoyard and Henry Torgue in the book, ‘Sonic Experience; A Guide to Everyday Sounds’, describe how and why they are thought to have been used:

“In the field of architecture, the use of resonators goes back to antiquity. The oldest Helmholtz-type resonators, called echeas, were used in Greek and Roman theatres. These resonators were described by Vitruve, a Roman architect in the first century BC, but there are no extant graphical representations; however, his description did stimulate the imagination of architects. These echeas, or brass vases, were tuned to the fourth, fifth and octave. Two types of vases were used simultaneously:

- The vases placed beside the stage, close to the actors, the dimensions of which could be important (170 centimetres at the Nova theatre, in Sardaigne) were used for amplification at the source

- The vases placed near the audience, produced a Haas effect - that is, a delay in the perception in the order of 1 to 30 milliseconds - that we now call artificial reverberation

Up to the end of the seventeenth century, acoustic vases were often used by architects, as demonstrated by clay pottery found in Roman churches. The shapes and dimensions varied greatly, but they were generally less than 25 centimetres tall. They have been found embedded in walls, at the base of arches, and sometimes even in the ground. More recently, this method was used in 1948 by the architect Andre Le Donne in the reconstruction of the arch of Notre-Dame du Rosaire in Le Havre. (Hundreds of ceramics were embedded in the concrete arch. Later, the church was transformed into apartments; the space located under the vault is now an attic.) The usefulness of these resonators has been revived today because their invisible and easily reproducible features make them convenient solutions in both acoustic and architectural contexts.”

(Jean-Francois Augoyard and Henry Torgue, ‘Sonic Experience; A Guide to Everyday Sounds’ trans. Andra McCartney & David Paquette, McGill-Queen’s University Press, Montreal & Kingston, London, Ithica, 2005. pgs 104-105)