The stone walls and floors of Norman and Gothic cathedrals produced not only an abnormally long reverberation time (six seconds or more) but also reflected sounds of low and medium frequencies as well, discriminating against high frequencies above 2,000 hertz owing to the greater absorption of the walls and air in that range. Anyone who has heard monks chanting plainsong in one of these old buildings will never forget the effect: the voices seem to issue from no point but suffuse the building like perfume.

Schafer, Murray R, The Soundscape- Our Sonic E…, loc. 418