Geometric acoustic numerical simulation showing a graphical representation of the propagation and build-up of sound from an impulse-like source at the west end of a 3D model of the now ruined St Mary’s Abbey Church in Museum Gardens (www.york.ac.uk/research/themes/ sixteenth-century-acoustics), York, UK. This image sequence shows the first 400ms of sound diffusion through the Abbey, with the full simulation indicating it takes nearly 6s for sound energy to decay beyond audibility. At the west end of the nave, reverberation dominates over direct sound, reducing intelligibility compared to locations nearer the source.