Don't use the e-mail address given in the presentation, but instead: web<dot>victor<dot>reijs@gmail<dot>com

1. MegaSound: Sound in
some Irish neolithic buildings
Victor Reijs, victor@reijs.org
First pan-American/Iberian meeting on acoustics
Cancun, Session 3aAA
December 4th
, 2002

2. Aim
 To share experience gained with acoustic
measurements in neolithic buildings and
 To get feedback for future work

3. Irish megalithic buildings
Dowth
Newgrange
Carrowkeel

4. Content
 The beginning...
 The measurements and neolithic buildings…
 The considerations and next steps...

5. The beginning
 Former interest in acoustics
 Speech analysis and synthesis (LPC)
 Interest in archaeocosmology
archaeoastronomy, archaeoacoustics, etc.
 Simulated by the book: Stone age soundtracks
Paul Devereux
 Asking people and The Internet for directions

6. The measurements
 Low frequency response (35 - 200 Hz)
 Reverberation times
 Calibration
 Tools…

7. Tools
 Software:
 ETF (http://www.etfacoustic.com/index.html)
MLS methodology
 Hardware:
 battery powered mains (2 hours)
 computer + audiocard
 sub-woofer system
 microphone

8. Irish neolithic buildings
 At least from 3000 BCE
 Fourknocks I
 Dowth South...
 Reconstructed neolithic dwelling...

9. Dowth South, Ireland

10. Reconstructed neolithic
dwelling

11. Considerations
 MLS methodology can provide more
information than single tones and/or using ears
(watch out for equal-loudness contours)
 No evidence that buildings were build on
purpose to colorate human pitch...
 Megalithic chambers sound much like modern
empty rooms
 Likely, neolithic man recognized different sound
experience in dwellings and megalithic
chambers and utilized it.

12.  In neolithic times humans were smaller
 human pitch range ~ 6% higher: 115 - 140 Hz
 Monte Carlo analysis in pitch range
chamber size: 1.5 - 6 [m], some 5500 runs
 Gilford-rules on modal coloration:
• major gap (>20 Hz) between axial modes: ~20%
• two axial modes in 5 Hz range: ~15%
 ~90% at least one axial mode!?
 Modal coloration occurs by chance in at least 30%
of cases
Coloration of human pitch

13. Considerations
 MLS methodology can provide more
information than single tones and/or using ears
(watch out for equal-loudness contours)
 No evidence that buildings were build on
purpose to colorate human pitch...
 Megalithic chambers sound much like modern
empty rooms
 Likely, neolithic man recognized different sound
experience in dwellings and megalithic
chambers and utilized it.

14. Next steps
 Analytic modelling:
 modes (theory)?
 frequency response (CARA)?
 auralization (CARA)?
 Measure unspoiled sites:
 e.g. Newgrange, Ireland

15. Acknowledgement
Thanks to the many people,
who helped in making my ideas
more clear
http://www.archaeocosmology.org/