Falling coins, striking matches and whispering voices to demonstrate the acoustics of an open air amphitheatre Project: Ancient Acoustics

Transcription

1 Falling coins, striking matches and whispering voices to demonstrate the acoustics of an open air amphitheatre Project: Ancient Acoustics Constant Hak Niels Hoekstra Bareld Nicolai Remy Wenmaekers University of Technology Eindhoven Department of the Build environment Unit Building Physics and Services

2 Herodes Atticus, Epidaurus and Argos

3 Project Ancient Acoustics Impulse response measurements Epidaurus number of microphone positions: source positions: measurements: : S1, S2 (5 rotations) : S1

4 Measurement and analysis Setup IR Process Result

5 Measurement and analysis Sound source directivity Example C Hz [db] 5 angles Average

6 Measurement and analysis Impulse response and quality Percentage of the measured impulse responses that exceed a certain decay range (INR)

7 More background info? Four papers presented at ICSV 2016 Hak, C.C.J.M., Hoekstra, N., Nicolai, B. & Wenmaekers, R.H.C. (2016). Project Ancient Acoustics Part 1 of 4 : a method for accurate impulse response measurements in large open air theatres. 23rd ICSV, July 2016, Athens, Greece (pp. 1-8). Hoekstra, N., Nicolai, B., Peeters, B.P.A., Hak, C.C.J.M. & Wenmaekers, R.H.C. (2016). Project Ancient Acoustics Part 2 of 4 : large-scale acoustical measurements in the Odeon of Herodes Atticus and the theatres of Epidaurus and Argos. 23rd ICSV, July 2016, Athens, Greece (pp. 1-8). van Loenen, R.C., van der Wilt, M., Diakoumis, A., Wenmaekers, R.H.C. & Hak, C.C.J.M. (2016). Project Ancient Acoustics Part 3 of 4 : influence of geometrical and material assumptions on ray-based acoustic simulations of two ancient theatres. 23rd ICSV, July 2016, Athens, Greece (pp. 1-8). Wenmaekers, R.H.C., Nicolai, B., Hoekstra, N. & Hak, C.C.J.M. (2016). Project Ancient Acoustics Part 4 of 4 : stage acoustics measured in the odeon of herodes atticus and the theatre of argos. 23rd ICSV, July 2016, Athens, Greece (pp. 1-8). Download via:

8 Do amphitheatres have extraordinary acoustics?

9 Extraordinary acoustics? Epidaurus described in a travel guide...wonderbaarlijk is de akoestiek. Tot op de achterste rij, 59 m verwijderd van het midden van de orchestra, waar de gids fluistert, enkele stappen zet, een papiertje scheurt, een lucifer aanschrapt, op de borst slaat, met de vingers knipt, een blad van een boek omslaat, een geldstuk laat vallen en diep zucht, zijn duidelijk alle geluiden te horen! Op de weekeinden in de zomermaanden worden er klassieke stukken opgevoerd; overal zijn de spelers duidelijk te verstaan, alleen is er dan wat nagalm... Dominicus reisgids Griekenland 1989

10 Extraordinary acoustics? Epidaurus described in a travel guide...the acoustics are extraordinary. Even on the back row, at a distance of 59 meters from the centre of the orchestra, where the tour guide whispers, walks around, tears a piece of paper, lights a match, beats his chest, snaps his fingers, turns a page of a book, drops a coin and sighs heavily, all sounds are clearly audible! During the summer weekends, classical plays are performed there: the players can be heard everywhere, although there is a bit of reverb... Dominicus travel guide Greece You could hear a pin drop...

11 Extraordinary acoustics? Epidaurus described in a travel guide...the acoustics are extraordinary. Even on the back row, at a distance of 59 meters from the centre of the orchestra, where the tour guide whispers, walks around, tears a piece of paper, lights a match, beats his chest, snaps his fingers, turns a page of a book, drops a coin and sighs heavily, all sounds are clearly audible! During the summer weekends, classical plays are performed there: the players can be heard everywhere, although there is a bit of reverb... Dominicus travel guide Greece You could hear a pin drop...

12 Extraordinary acoustics? true not true don t know...the acoustics are extraordinary. Even on the back row, at a distance of 59 meters from the centre of the orchestra, where the tour guide whispers, walks around, tears a piece of paper, lights a match, beats his chest, snaps his fingers, turns a page of a book, drops a coin and sighs heavily, all sounds are clearly audible! During the summer weekends, classical plays are performed there: the players can be heard everywhere, although there is a bit of reverb... Dominicus travel guide Greece You could hear a pin drop...

13 The small suitcase of the guide Measurement set for amfitheater acoustics?

14 Sound source versus background noise Epidaurus background noise level 35 db(a) Dry Just Noticeable Recogniseable (JN+10 db)

15 Sound level match (just noticeable) db(a) LwA = 57,1 db(a) Impulse 30 ms - 15

16 Sound level match (recogniseable) db(a) LwA = 57,1 db(a) Impulse 30 ms - 15

17 Sound level coin (Just noticeable) db(a) LwA = 60,4 db(a) Impulse 30 ms - 15

18 Sound level coin (recogniseable) db(a) LwA = 60,4 db(a) Impulse 30 ms - 15

19 Sound level paper (just noticeable) db(a) LwA = 61,3 db(a) Impulse 30 ms - 15

20 Sound level paper (recogniseable) db(a) LwA = 61,3 db(a) Impulse 30 ms - 15

21 Sound level whispering (just intelligible) db(a) LwA = 52,2 db(a) Impulse 30 ms - 15

22 Sound level needle (hearing threshhold) db(a) LwA = 21,4 db(a)

23 Extraordinary acoustics? true not true don t know...the acoustics are extraordinary. Even on the back row, at a distance of 59 meters from the centre of the orchestra, where the tour guide whispers, walks around, tears a piece of paper, lights a match, beats his chest, snaps his fingers, turns a page of a book, drops a coin and sighs heavily, all sounds are clearly audible! During the summer weekends, classical plays are performed there: the players can be heard everywhere, although there is a bit of reverb... Dominicus travel guide Greece You could hear a pin drop...

24 Extraordinary acoustics? true not true don t know...the acoustics are extraordinary. Even on the back row, at a distance of 59 meters from the centre of the orchestra, where the tour guide whispers, walks around, tears a piece of paper, lights a match, beats his chest, snaps his fingers, turns a page of a book, drops a coin and sighs heavily, all sounds are clearly audible! During the summer weekends, classical plays are performed there: the players can be heard everywhere, although there is a bit of reverb... Dominicus travel guide Greece 1989

25 Measurement result Speech intelligibility Evening Avond Infinite silence Very loud voice Normal voice bad poor fair good excellent 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0

26 Extraordinary acoustics? true not true don t know...the acoustics are extraordinary. Even on the back row, at a distance of 59 meters from the centre of the orchestra, where the tour guide whispers, walks around, tears a piece of paper, lights a match, beats his chest, snaps his fingers, turns a page of a book, drops a coin and sighs heavily, all sounds are clearly audible! During the summer weekends, classical plays are performed there: the players can be heard everywhere, although there is a bit of reverb... Dominicus travel guide Greece 1989 Theater performance at a historic place in the open air/nature More than 10,000 silent people The ease with which players speak very loudly

27 Thanks for your attention! Adonia Constant Niels Chris Bareld Bas Remy Marco Diakoumi Hak Hoekstra Van Loenen Nicolai Peeters Wenmaekers van der Wilt Argos Herodes Attucus Epidaurus