Comb Filtering ( Archaeoacoustics )

Researcher conducts experiments to support his theory that acoustics influenced the design of Stonehenge .
He rigged up an air pump to play two flutes tuned to the same pitch ( presumably replicas of bone or wood )and blindfolded volunteers who were led around a circle orbiting the flutes . Afterwards they were asked to describe the experience :-

Interesting. I doubt there’s much to it but it makes for a nice read. The pattern you get is very dependant of the frequency of those flutes anyway.

Would’ve liked to see one of those drawings though.

I’d be curious to know which recreational drug he prefers.