In the framework of opera house acoustics, the term “balance” refers to the acoustical competition between the singer on the stage and the orchestra in the pit. The mechanism allowing the operatic singers to be heard over the orchestra has to do with their skill in enhancing the vocal emission by a peculiar use of the formant frequencies. This vital factor is sensed by the listeners and, apart from the obvious sound power ratio of the stage and the pit sources, is the main cue that helps to formulate a subjective impression of the balance. To achieve its objective qualification, two calibrated sound sources can be placed on the stage and in the pit, respectively, and their sound level difference is measured at the listeners’ seats. The scope of this work is to investigate the relationship between the subjective impression and the objective indicator of the balance and to develop a scale value for the parameter in the case of a historical opera house. For this scope a set of acoustical data from the Teatro Comunale in Ferrara will be used to create synthetic sound fields with controlled conditions of the balance between the stage and the pit. This methodology employs an anechoic piece for soprano (with piano accompaniment) and is implemented in a dead room equipped with an acoustical rendering system. The sound fields are used to investigate the appropriate balance values by means of listening tests. The results of the scaling exercise show that a suitable range of values can be extracted and that the sound from the stage and the pit is perceived as balanced when the loudness difference between the two is comprised within −2.0 dBA and +2.3 dBA.

1.
J. Meyer, “Some problems of opera house acoustics,” Proceedings of the 12th I.C.A., Vancouver, 1986.
2.
J.
Sundberg
, “
The acoustics of the singing voice
,”
Sci. Am.
236
,
82
91
(
1977
).
3.
J.
Sundberg
, “
Level and center frequency of the singer’s formant
,”
J. Voice
15
,
176
186
(
2001
).
4.
J. Sundberg, “Research on the singing voice in retrospect,” Speech, Music and Hearing, KTH Stockholm TMH-QPSR, 2003, Vol. 45, pp. 11–22.
5.
M. Barron, Auditorium Acoustics and Architectural Design (E & FN Spon, London, 1993), p. 333.
6.
J. O’Keefe, “Measurement of stage to pit balance in four proscenium arch theatres,” Proceedings of IOA—Auditorium Design at the Millennium, Belfast, 1997.
7.
ISO/DIS 3382, Measurement of Reverberation Time With Reference to Other Acosutical Parameters (International Organization fo Standardization, Geneve, 1997).
8.
Theater’s site: http://www.teatrocomunaleferrara.it/
9.
L. Parati and F. Otonto, “Comparison of directional sources in simulating a soprano voice,” Proceedings of SMAC2003, August 2003, Stockholm, Sweden.
10.
L. Parati, “Acoustical balance between singer on the stage and orchestra in the pit,” Cap. 3, Ph.D. thesis, Facoltà di Ingegneria, Università degli Studi di Ferrara, A. Y. 2002, 2003.
11.
J.
Cox
,
W. J.
Davies
, and
Y. W.
Lam
, “
The sensitivity of listeners to early sound field changes in auditoria
,”
Acustica
79
,
27
41
(
1993
).
12.
O.
Kirkeby
,
P. A.
Nelson
, and
H.
Hamada
, “
Local sound field reproduction using two closely spaced loudspeakers
,”
J. Acoust. Soc. Am.
104
,
1973
1981
(
1998
).
13.
Y. Ando, Architectural Acoustics: Blending Sound Sources, Sound Fields and Listeners (Springer-Verlag, New York, 1998), p. 34.
14.
N. Prodi, R. Pompoli, and L. Parati, “The acoustics of the Municipal Theatre in Modena,” Proceedings of the Forum Acusticum 2002, Seville, September 2002.
15.
T. Takeuchi and P. A. Nelson, “Subjective evaluation of the Optimal Source Distribution system for virtual acoustic imaging,” Proc. of the AES 19th International Conference, Schloss Elmau, Germany, June 2001.
16.
N.
Prodi
and
S.
Velecka
, “
The evaluation of playback systems for virtual sound fields
,”
Appl. Acoust.
64
,
147
161
(
2003
).
17.
W. S. Torgerson, Theory and Methods of Scaling, 7th printing (Wiley, New York, 1967), Chap. 10.
18.
W. Yost and D. W. Nielsen, Fundamentals of Hearing, an Introduction (Italian edition) (Piccin, Padova, 1986), p. 147.
19.
A. L.
Edwards
and
L. L.
Thurstone
, “
An internal consistency check for scale values determined by the method of successive intervals
,”
Psychometrika
17
,
169
180
(
1952
).
20.
M. Barron, “The value of ISO3382 for research and design,” Proceedings of IOA—Auditorium Acoustics, London, 2002, Vol. 24, Part 4.
21.
G. Iannnace, C. Ianniello, L. Maffei, and R. Romano, “The measurement of G in auditoria: comparing two techniques,” Proceedings of the 23rd Congress of the Italian Acoustics Association, Genova, May 1999 (in Italian).
22.
D. G.
Ciric
and
M. A.
Milosevic
, “
Inaccuracies in sound level determination from room impulse response
,”
J. Acoust. Soc. Am.
111
,
210
216
(
2002
).
This content is only available via PDF.
You do not currently have access to this content.