The 110 Hz figure below is not supported by the measurement this page implies. Rupert Till's sine-sweep survey of the Hypogeum (University of Huddersfield eprint 30678) identifies resonances at 41, 72, 75–76, 134, 161, 186 and 196 Hz. 110 Hz is not among them; the nearest reported peak is 134 Hz, more than eighty modal linewidths away. Till's paper contains no mention of 110 Hz and none of the Cook/Ezra/Shearer EEG study cited below.
Till reports reverberation of 14.62 s at 63 Hz, and is explicitly non-committal about whether the acoustics were engineered: the Oracle niche "may have been created to mark the position as being of particular acoustic interest…or may have simply related to the presence of a statue."
This page is kept as what it is — a tone generator. A 110 Hz drone is a perfectly good thing to listen to. It is not a measurement of this chamber. The physics is worked through in Vol VII · André Nachbin, with arithmetic in ch-nachbin-acoustics-verify.py.
Oracle Chamber · 90–120 Hz tone sweep · see correction on 110 Hz · 3600 BCE Malta
Resonant band sweep · 90–120 Hz
90 Hz
120 Hz105.0 Hz
30 s
110.0 Hz
Chamber acoustics
60%
600 Hz
4.0 Hz
70%
The Ħal Saflieni Hypogeum in Malta (c. 3600–2500 BCE) is the only known prehistoric underground temple. Its Oracle Chamber exhibits a resonant peak at approximately 110 Hz — documented by archaeoacoustician Iegor Reznikoff and later measured by Cook, Ezra and Shearer (2008), who also recorded EEG shifts in subjects, specifically a shift from left to right prefrontal dominance associated with altered states and heightened receptivity.
The full resonant band is 90–120 Hz. Sweeping through this band approximates the effect of a voice or instrument being moved through the chamber — each sub-frequency excites different standing wave nodes in the limestone walls. 110 Hz is the peak but not the whole experience.
The binaural beat adds a second oscillator offset by the specified Hz, creating a perceived pulse in the difference frequency — 4 Hz corresponds to theta brainwaves (deep relaxation, meditation).
Ready — sweep mode · 90–120 Hz Oracle Chamber band