CIP A 2003 XIX th International Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
234 
has no influence in the auditorium or on the balance. The 
influence of it is reflected on the equilibrium between singer- 
conductor-orchestra. This side of the barrier is responsible for 
the early reflections reaching the singer from the orchestra and 
to the conductor from the singer. The tested materials combined 
with different pit levels showed their influence. In the results 
the difference can clearly be seen with a pit level of 1.5 m at the 
singer’s receiver position. In this particular case the increasd 
level of the orchestra at the singer’s ears is not strong enough to 
disturb the singer. Stronger values could press the singer to 
force his voice, because of the feedback he receives from the 
orchestra, with bad results at the listener’s positions. 
Parati, L. Otondo, F., 2003. Comparison of directional sources 
in simulating a soprano voice. In: Proceedings of SMAC03, 
Stockholm. 
Prodi, N., Pompoli, R., 1999. Acoustics of opera houses: a 
cultural heritage. In: Proceeding of Forum Acoustic, Berlin. 
Prodi, N., Pompoli, R., 2000. Guidelines for acoustical 
measurements inside historical opera houses: procedures and 
validation. Journal of Sound and Vibration, Vol. 232-1. 
Rindel, J.H., 2000. The use of computer modelling in room 
acoustic. Journal of vibroengineering, Vol. 3, pp 219-224. 
Royal Theatre of Copenhagen home page, http://www.kgl- 
teater.dk . 
Sundberg, J., 1977. The acoustics of the singing voice. Scient. 
Amer. 236, pp 82. 
5. ACKNOWLEDGMENTS 
This work has been financed by a Marie Curie Fellowship as a 
part of the programme European Doctorate in Sound and 
Vibration Studies. 
The authors wish to thanks the Royal Theatre of Copenhagen 
for the availability demonstrated. 
Fig 5 Example of a reflection given by the back wall of the pit. 
3. CONCLUSION 
The new techniques seem to be useful to determine suitable 
changes to improve the acoustical heritage of an historical opera 
house without affecting important historical architectural 
elements. 
By means of the simulation it has been found that the Balance 
between singer and orchestra can be controlled by the surfaces 
of the pit. The pit level influences the sound pressure level in 
the stalls, while changing the pit materials produces notable 
effects throughout the hall. 
The pit fence and the pit level can affect the equilibrium 
between singer-conductor-orchestra and not the balance. 
The stage’s slope has minor influence on the balance. 
To date, the results presented in this study have been for one 
model. Future work will include testing in additional models to 
investigate the general validity of the techniques suggested in 
this paper. 
4. REFERENCES 
IS03382: 1997, Acoustic - Measurement of the reverberation 
time of rooms with reference to other acoustical parameters. 
Lynge Christensen, C., 2001. Odeon - a design tool for 
auditorium acoustics, noise control and loudspeaker system. 
Proceedings of the Institute of Acoustics, Vol. 23, pp. 137-144. 
Meyer, J., 1986. Some problems of opera house acoustics. In: 
Proceedings of 12 th ICA, Vancouver. 
Odeon home page, http://www.odeon.dk