After historical research has applied to the visual aspects of human perception for a long time now, as of recently the investigation of acoustic matters arouse an increased scientific interest too.1 So far still largely unresearched has been the concrete speech situation in premodern times before electro-acoustic amplification. In a large-scale study the department of ancient history in close collaboration with acousticians of the Frauenhofer-institute as well as other research disciplines attempts to adequately reconstruct and simulate ancient historic speech situations.

1. Beyond the visual.
The acoustic reconstruction and simulation of ancient
senate sessions
Dr. des. Christian Fron
University of Stuttgart
Department of ancient history
Abteilung Alte Geschichte
06. January 2016

2. Introduction

3. outline
1. short introduction
2. the curia Iulia as research project
3. An acoustic simulation: our approach
4. results and further questions

4. the curia Iulia as research project
• 52 BC: The senate building burns and P. Clodius Pulcher with it.
• By no later than 45/44 BC and in the context of the construction of the Forum Iulium a
new Curia is enacted.
• 29 BC: The curia Iulia is dedicated by Octavian, the later Augustus.

5. the curia Iulia as research project

6. the curia Iulia as research project

7. the curia Iulia as research project

8. the curia Iulia as research project
“1. The treasury, prison, and senate house ought to adjoin the
forum, but in such a way that their dimensions may be
proportionate to those of the forum. Particularly, the senate house
should be constructed with special regard to the importance of the
town or city. If the building is square, let its height be fixed at one
and one half times its breadth; but if it is to be oblong, add
together its length and breadth and, having got the total, let half of
it be devoted to the height up to the coffered ceiling.
2. Further, the inside walls should be girdled, at a point halfway up
their height, with coronae made of woodwork or of stucco.
Without these, the voice of men engaged in discussion there will
be carried up to the height above, and so be unintelligible to their
listeners. But when the walls are girdled with coronae, the voice
from below, being detained before rising and becoming lost in the
air, will be intelligible to the ear.” (Vitr. 5,2,1f.)

9. the curia Iulia as research project
[17,75 m (w) + 25,63 m (l)]/2 = 21, 69 m (height
according to Vitruvius).
approximate real height: 23,40 m

10. outline
1. short introduction
2. the curia Iulia as research project
3. An acoustic simulation: our approach
4. results and further questions

11. An acoustic simulation: our approach
http://www.odeon.dk/
http
://www.odeon.dk/archaeological-acoustics-open-theat
re#

12. An acoustic simulation: our approach

13. 13
reflexion of sound
barrier (f.i. wall)sound
wave

14. 14
absorption of sound (decreased reflexion of
sound)
barrier (f.i. wall)

15. 15
transmission of sound (sound absorbtion)
barrier (f.i. wall)

16. 16
reflexion + transmission
f.i. window
lower frequencies
higher frequencies

17. An acoustic simulation: our approach
 view inside of the Curia
 1: benches
 2: entrance
 3: niches
 4: cornices
 5: windows
 6: coffered
ceiling
 7: open space
before the door

18. An acoustic simulation: our approach
Absorption coefficients
Frequency (Hz)
63 125 250 500 2000 8000
Alpha
0.96
0.8
0.64
0.48
0.32
0.16
Odeon©1985-2015 Licensed to: Fraunhofer-Institut für Bauphysik, Germany

19. An acoustic simulation: our approach
 Speaker P (cross)
 P1: podium (active)
 P2: groundlevel aisle
 P3: first step
 audience (blue points)
 M1: Podium
 M2: in front on first
step
 M3: middle on first step
 M4: middle on
groundlevel
 M8: in a corner
 M5: 1 m in front of the
door
 M6: 4 m in front of the
door
 M7: 8 m in front of the
door

20. outline
1. short introduction
2. the curia Iulia as research project
3. An acoustic simulation: our approach
4. results and further questions

21. results and further questions
Situation resp.
Sound source
distance
Sound pressure p
in Pascal
Sound pressure Lp
in Dezibel
Disco 1 m 2 Pa 110 dB
Hearing damage if
heard for a longer
time
ear ab 0,36 Pa 80 dB
Main road 10 m 0,2 – 0,63 Pa 75 dB
TV 1 m 0,02 Pa 70 dB
Dialoge partner
(normal
conversation)
1 m 2 · 10−3
– 2 · 10−2
Pa 55 dB
Very quiet room ear
2 · 10−4
– 6,3 · 10−4
Pa
45 dB
breathing ear 6,32 · 10−5
Pa 10 dB

22. results and further questions
Redner P1 (emperor, red cross): ca. 56 dB (A) on 1 m
 Ist: actual state; door closed. With cornices
 OG: without cornices; door closed.
 TO: door opened; with cornices.
Pos. SPL dB (A)
Ist/OG/TO
STI
Ist/OG/TO
M1 64.6/64.6/64.6 0.85/0.86/0.86
M2 53.1/53.0/52.9 0.52/0.51/0.52
M3 53.1/51.2/50.9 0.46/0.45/0.47
M4 51.6/51.4/51.4 0.37/0.35/0.37
M8 51.1/51.5/50.3 0.50/0.45/0.45
M5 (1m) - / - /46.8 - / - /0.40
M6 (4m) - / - /43.1 - / - /0.38
M7 (8m) - / - /39.3 - / - /0.38
average 0.46/0.44/0.45
0 8 16 24 32 40 metres
0
5
10
15
20 metres
P1P1P2
P3
P1
1
3
2
333
4
3
5
3
6
3
7
3
8
3
P1
Odeon©1985-2015 Licensed to: Fraunhofer-Institut für Bauphysik, Germany

23. results and further questions
 Speaker P2 (red cross): ca. 56 dB (A) bei 1 m
 Ist: actual state; door closed. With cornices
 OG: without cornices; door closed.
 TO: door opened; with cornices.
Pos. SPL dB (A)
Ist/OG/TO
STI
Ist/OG/TO
M1 54.8/54.5/55.0 0.56/0.57/0.55
M2 57.4/57.2/57.3 0.66/0.68/0.67
M3 51.2/51.1/50.9 0.41/0.38/0.42
M4 53.2/53.0/52.9 0.46/0.46/0.47
M8 50.7/50.8/50.8 0.44/0.41/0.51
M5 (1m) - / - /47.0 - / - /0.42
M6 (4m) - / - /43.5 - / - /0.41
M7 (8m) - / - /39.0 - / - /0.39
average 0.51/0.50/0.52
0 5 10 15 20 25 30 35 metres
0
5
10
15
20
25 metres
P2
1
2
3
4
567
8
P2
Odeon©1985-2015 Licensed to: Fraunhofer-Institut für Bauphysik, Germany

24. results and further questions
Speaker P3 (red cross): ca. 56 dB (A) bei 1 m
 Ist: actual state; door closed. With cornices
 OG: without cornices; door closed.
 TO: door opened; with cornices.
Pos. SPL dB (A)
Ist/OG/TO
STI
Ist/OG/TO
M1 51.9/51.9/51.8 0.45/0.43/0.45
M2 52.5/52.4/52.4 0.50/0.49/0.51
M3 53.3/53.2/53.0 0.52/0.52/0.53
M4 54.7/54.7/54.5 0.59/0.59/0.6
M8 51.4/51.5/51.2 0.46/0.45/0.46
M5 (1m) - / - /47.2 - / - /0.43
M6 (4m) - / - /43.9 - / - /0.46
M7 (8m) - / - /41.4 - / - /0.52
average 0.50/0.49/0.51
0 8 16 24 32 40 metres
0
5
10
15
20 metres
P3
P1P2
P3P3
1
3
2
333
4
3
5
3
6
3
7
3
8
3
P3
Odeon©1985-2015 Licensed to: Fraunhofer-Institut für Bauphysik, Germany

25. results and further questions
 speaker 2
 listener 1 (emperor),
 Free field
 emperor
P2
P1
P2
P3
P2
11
2
1
3
1
4
1
5
1
6
1
7
1
8
1
P2
Odeon©1985-2015 Licensed to: Fraunhofer-Institut für Bauphysik, Germany Restricted version - research and teaching only

26. Thank you very much for your attention.

27. Thank you very much for your attention.
Reference:
• Background: modification of the fresco of Cesare Maccari „Cicéron dénonce Catilina“
• Slide 2: http://
www.digitales-forum-romanum.de/wp-content/uploads/2014/03/A-8-0201_JKLMNO_Curia-Iulia_Kontext.jpg
• Slide 4: http://
www.digitales-forum-romanum.de/wp-content/uploads/2014/03/7-Phase-G_Sp%C3%A4te-Republik-I_Draufsicht.jpg
and http://www.digitales-forum-romanum.de/wp-content/uploads/2014/02/7-Phase-L_Augusteisch-II_Draufsicht.jpg
• Slide 5: http://
www.digitales-forum-romanum.de/wp-content/uploads/2014/03/A-10-0201_EFGH_Curia-Hostilia_isometrisch.jpg and
http://www.digitales-forum-romanum.de/wp-content/uploads/2014/03/A-11-0201_I_Curia-Cornelia_isometrisch.jpg
and http://
www.digitales-forum-romanum.de/wp-content/uploads/2014/03/A-12-0202_JKLMNO_Curia-Iulia_isometrisch.jpg and
http://
www.digitales-forum-romanum.de/wp-content/uploads/2014/03/A-13-0202_PQRS_Curia-Diocletiani_isometrisch.jpg
• Slide 6:
http://www.acsearch.info/image.html?id=1713375
• Slide 7:http://
dlib.etc.ucla.edu/projects/Forum/assets/media/reconstructions/CuriaIulia_1/CuriaIulia_1_Inside_HiRes.jpg
and http://www.jeffbondono.com/TouristInRome/RomeImages/IMG_1592-IMG_1595-20131006.jpg
and image by google earth

28. Thank you very much for your attention.
Reference:
• Slide 9:
http://farm8.staticflickr.com/7102/7356011222_724dc4d7a4_b.jpg
• Slde 11:
Odeon-Model of the Curia Iulia from the Fraunhofer Institute of building physics and acoustics by Xiaoru Zhou
• Slide 12:
Google SketchUp model of the Forum Romanum from the Fraunhofer Institute of building physics and acoustics by
Xiaoru Zhou
• Slide 13-16:
Slides by Prof. Dr. Philip Leistner
• Slide 17:
Odeon-Model of the Curia Iulia from the Fraunhofer Institute of building physics and acoustics by Xiaoru Zhou
• Slide 19:
Odeon-Model of the Curia Iulia from the Fraunhofer Institute of building physics and acoustics by Xiaoru Zhou
• Slide 21:
http://www.welt.de/print-welt/article334313/Vom-Ticken-der-Uhr-bis-zum-Presslufthammer.html and http://
www.fohonline.com/images/stories/15/02/current-foh/techfeature/intelligibility%20scale.jpg
• Slide 22-25:
Additional Model and acoustic simulations from from the Fraunhofer Institute of building physics and acoustics by
Xiaoru Zhou