The effect of ceramic vases on the acoustics of old Greek orthodox churches

The effect of resonators on the acoustics of orthodox churches was studied. Empty bottles of commercial refreshment were used as resonators. A total number of 480 resonators having the same resonant frequency, were placed inside a church, in steps of 100 resonators each time, and the impulse response of the church was measured and analyzed in 1/1 and 1/3 octave band analysis. The effect of resonators is rather poor. An amplification of sound in the near field of resonators was observed as well as a small attenuation of the sound level in the reverberant part of the field in the resonant frequency and near to a higher overtone. A remarkable increase of C80 and D50 at resonant frequency was also observed.