Looking across the standing stones of the Ring of Brodgar with the Loch of Harray beyond.
 
 

Acoustics at the Ring of Brodgar

I first worked with David Keating at the Ring of Brodgar in 1998. This large stone circle is set within a rock-cut ditch and an outer bank or wall which has not survived. As many as 60 stones may once have stood around its 100m diameter, although fewer than half of remain today. Even so, the monument has distinctive acoustic qualities.

Similar to the Stones of Stenness nearby, echoes here are dynamic. In contrast to Stenness, however, sounds at the Ring of Brodgar have to be louder to travel across the large circle and are more subject to influence from wind and rain. It was noted that echoes produced by handclapping or vocalising travel clearly across the circle in calm weather, but percussive noises and drums were most effective in all weather conditions.

Recording echoes within the Ring of Brodgar.

The character of these echoes also varies in relation to the location of the sound source and the listener. The most dramatic effect was heard when both the sound source and listener were at the centre of the monument. Here, the sound returned from all stones of the circle simultaneously, creating an unusual ’surround-sound’ effect. The delay is about one-third of a second, which is long enough to create percussive compositions where the player is effectively accompanied by the echoes returning from the stones.

 
The large and tabular stones at the Ring of Brodgar reflect sound, creating distinctive echoes.
 
 

As the listener moves away from the centre of the circle the effect becomes diffused because the echo has to travel variable distances between the source and stones. This causes the echoes to lose coherence, and emphasises the centre as a special focus for sound making. Outside the circle, the echo effect is lost altogether.

Further reading

Watson, A. and Keating. D. 2000. The architecture of sound in Neolithic Orkney. In A. Ritchie (ed.) Neolithic Orkney in its European context, 259-63. Cambridge: McDonald Institute Monographs.