SBResearch group presents the preliminary results of the experiment which tested the effects of resonant frequencies (from the hypogeum of Hal Saflieni) on brainwave frequencies and consciousness.
Some ancient structures have psychoacoustic effects on human brain which alter the brainwave frequency.
Our study aims to show that the differences between the acoustics of Hal-Saflieni and a modern auditorium are perceptible even though both sites may have the same reverb time. Listening tests will be designed and conducted for data collection. Population will be selected among mixed students from audio-related courses (expert listeners).
Listening tests have been conducted on an expert panel of 13 subjects. The subjects completed 10 trials of an ABX test. The samples were 30 second sine sweeps [(logarithmic) from 65 Hz to 130 Hz (1 octave as resonances were found in this region in other studies, eg: 110 Hz)] convoluted with the impulse responses of the Cathedral of St. Etienne and Hal-Saflieni hypogeum. The RT60 for St Etienne is 7.81s and Hal Saflieni is 7.78s.
Convolution processing using Audioease Altiverb 6.1.2