~Proceedings ICMCISMCI2014 14-20 September 2014, Athens, Greece
L ~ r~ ~ k...
(1.k*m.ST
(b)
(c)
Figure 15. RASTI comparison between non-masked and
masked speaker at the (a) on-axis listening positions R1
(15.6 m), R4 (29.4 m) and R7 (47.6 m), (b) O; = 450 listening positions R2 (15.6 m), R5 (29.4 m) and R8 (47.6
m) and (c) O; = 900 listening positions R3 (15.6 m), R6
(29.4 m) and R9 (47.6 m).
3.2.3 Simulations and auralisation
Based on the schematic of Figure 9, auralisations were
produced using monaural audio files of typical speech.
For these responses obtained from measurements, the
source position was assumed to be at S 1 (see Figures 8
and 9(a)). Furthermore, using simulations [3] of the theatre of Epidaurus in its original form (i.e. with the stage
building), binaural auralisation files were also produced
for the source at position S 1 and also at S2. The acoustic
properties of the masks (frequency response and directivity characteristics) were introduced in the simulation computer model allowing the auralisation at any desired position on the tiers. Audio demonstrations of such
simulations will be given during the presentation of this
work [16].
4. CONCLUSIONS
The study of the spectral and radiation sound effects of
masks employed by actors performing in the typical ancient Greek theatre of Epidaurus, has provided some clear
evidence for the acoustic function of such masks that
were always used during the ancient drama performances
by the (male) actors.
Using template masks constructed from archeological
evidence, their measured frequency and angle-dependent
response was combined with measured acoustic impulse
responses of the theatre for various positions. Thus, these
simulated tests generated the combined mask-theatre responses and also the corresponding speech sounds at the
desired audience positions.
Analysing these combined mask-theatre responses, it was
found that the masks amplified the spectral region up to
1000 Hz. This effect was found to be stronger around the
male speech fundamental frequency. Given that the theatre responses present a significant peak around the mid
1000 Hz region, the "mask-filter" effect appears somehow to smooth the overall spectral profile of the "theatrefilter". Furthermore, the masks would alter the actor's
voice by boosting the low-mid region of speech reaching
the audience.
In addition to that, the masks were found to enhance directivity for the side of the actor's head and hence amplify significantly such low-mid speech frequency region,
for listeners located beyond the central positions and especially at the sides of the cavea. This radiation property
of the masks would improve reception at these more
problematic audience positions, especially under noisy
conditions. However, under normal conditions, the masks
were not found to affect the excellent speech intelligibility of the Epidaurus theatre which has remained perfect
for all listener positions.
Further in-situ impulse response measurements of the
masked manikin in the theatre of Epidaurus would be a
desirable addition to the present study and are left for
future work. Moreover, binaural recordings of a masked
actor performing in the theatre may also allow more realistic demonstrations of the acoustic experience of the
ancient Greek spectators in such theatres and hence compliment this work.
Acknowledgments
This research has been co-financed by the European Union through the European Social Fund, ESF, and the
Greek national funds through its Operational Program
Education and Lifelong Learning of the National Strategic Reference Framework, NSRF. Research Funding Programs: Thalis-University of Athens-Erasitechnis, grant
number: MIS 375435.
5. REFERENCES
[1] Shankland, S. Robert. Acoustics of Greek theaters,
Physics Today, 1973, pp. 30-35
[2] F. Canac, "L'acoustique des thatres antiques",
published by the CNRS, Paris, 1967
[3] S. L.Vassilantonopoulos, J. N. Mourjopoulos, "A
Study of Ancient Greek and Roman Theater
Acoustics", Acta Acustica united with Acustica, 89,
2002.
[4] T. Vovolis, "Prosopon, the acoustical mask in Greek
Tragedy and in Contemporary Theatre", Dramatiska
Institutet, Stockholm (2009)
[5] C. Vervain and D. Wiles, "The Masks of Greek
Tragedy as Point of Departure for Modern
Performance", New Theatre Quarterly 17(2), 254 -272, 2001
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