- Email: [email protected]
Measurement of intelligibility and clarity of the speech in romanesque churches
G Model CULHER-2877; No. of Pages 5
ARTICLE IN PRESS Journal of Cultural Heritage xxx (2014) xxx–xxx
Available online at
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Case study
Measurement of intelligibility and clarity of the speech in romanesque churches Pavol Brezina ∗ Department of Music, Constantine the Philosopher University in Nitra, Tr. A. Hlinku 1, 94901 Nitra, Slovakia
a r t i c l e
i n f o
Article history: Received 1st March 2014 Accepted 19 June 2014 Available online xxx Keywords: Acoustics Romanesque churches Cultural heritage Speech intelligibility Architecture
a b s t r a c t Intelligibility and clarity of the speech are important acoustic parameters of sacred spaces, such as churches and temples. The study focuses on the description of the acoustic characteristics of Romanesque churches with a matroneum from the 10th up to the 12th century and compares the results of measurements taken from different positions intended for speech recitation. From the complex acoustic research, the case study focuses on the presentation of the results of measurements of clarity and intelligibility of the speech via acoustic field research. The research objects are three important Romanesque churches with a matroneum in Slovakia–Christian Reformed Church in Kalinˇciakovo, St. Stephen-King Church in Nitra and the Our Lady Queen of Angels Church in Sádok. The aim of the research is to highlight not just the differences but also the commonalities of the selected acoustic parameters of these churches. © 2014 Elsevier Masson SAS. All rights reserved.
1. Introduction The Romanesque cultural heritage is one of the primary research objects in archeology, history, restoration, art and architecture. Its extensive archaeological and historical-artistic research has recently started to increasingly encompass acoustic research, too. Firstly, it comes to describing the basic acoustic properties of the space by measuring various acoustic parameters. From the Romanesque period, among the most frequently studied spaces are ancient theatres [1] and sacred buildings [2]. In addition to the characteristics of the acoustic properties, the research also deals with virtual acoustic environment simulation, and some of the studies are devoted to the specific research of historical buildings in terms of human speech intelligibility and musical interpretation [3]. The possibility of keeping such virtual models as intangible cultural heritage has also begun to be discussed [4]. This case study is devoted to the research of intelligibility of the speech in smaller Romanesque churches with a matroneum. In churches, the speech is currently most frequently uttered from the area in front of the altar, but in the past the specific raised points, such as the pulpit, were the dominant place, especially during sermons. The measurement and comparison of the intelligibility of speeches given from selected places in the church compare the level of functionality of these places via a new scientific perspective. The primary objective of this case
∗ Tel.: +421904247459. E-mail addresses: [email protected], [email protected]
study is to document the important acoustic parameters of smaller Romanesque churches, which are important historical monuments of Central Europe. Similar research has not as yet been conducted. This is also research which documents the acoustics of important cultural sites as a form of intangible cultural heritage.
2. Research objects The selected research objects (Fig. 1) were the oldest preserved Romanesque churches in Slovakia–Christian Reformed Church in Kalinˇciakovo (a), St. Stephen-King Church in Nitra (b) and the Our Lady Queen of Angels Church in Sádok (c). The history of the Christian Reformed Church (volume: 272 m3 ) in Kalinˇciakovo dates back to when it was built in the first half of the 12th century. It is now one of the most important Romanesque buildings in Slovakia. Originally, the Roman Catholic Church dedicated to St. Anne was violently taken by the Calvinists in 1655 [5]. Reconstruction works on site were carried out in 1932, 1956 and 2003 [6]. From a construction point of view, the church consists of a Romanesque apse and a nave. St. Stephen-King Church in Nitra (volume: 316.8 m3 ), located in the neighbourhood of Párovce, is a characteristic singlenave building with a matroneum and a semicircular apse [7]. The church stood in this place probably in the 10th century. In the 11th and 12th century, it was rebuilt in the Romanesque style [8]. Until 1992, the church was seldom used and fell into disrepair. The change came on 1st September 1992, when it was rented to the Greek Catholic Church [9]. Several changes then took place inside the church, the most striking one being the space adaptation for
http://dx.doi.org/10.1016/j.culher.2014.06.010 1296-2074/© 2014 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010
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ARTICLE IN PRESS P. Brezina / Journal of Cultural Heritage xxx (2014) xxx–xxx
Fig. 1. Exterior and interior photos of churches. (a): Christian Reformed Church in Kalinˇciakovo; (b): St. Stephen-King Church in Nitra; (c): Our Lady Queen of Angels Church in Sádok.
Fig. 2. Part A: church floor plans indicating the location of sound sources (S) and microphone positions (p). (a): Christian Reformed Church in Kalinˇciakovo; (b): St. StephenKing Church in Nitra; (c): Our Lady Queen of Angels Church in Sádok. Part B: reverbation time (T30, T20), early decay time (EDT) and the centre of impulse response (Ts) measured values for individual churches.
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010
G Model CULHER-2877; No. of Pages 5
ARTICLE IN PRESS P. Brezina / Journal of Cultural Heritage xxx (2014) xxx–xxx
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Fig. 3. Part A: graphs of relations of speech transmission index (STI) values for the sound source positions S1 and S2 . (a): Christian Reformed Church in Kalinˇciakovo; (b): St. Stephen-King Church in Nitra; (c): Our Lady Queen of Angels Church in Sádok. Part B: subjective speech intelligibility assessment scale and range of STI measured values for individual churches.
Greek Catholic worship and the placement of an iconostasis in the area of the apse. The choir loft of the church is well preserved and no organ is present in it. Our Lady Queen of Angels Church in Sádok (volume: 635 m3 ) is an important architectural cultural monument
in Slovakia. It is a one-nave building dating to the period of the second half of the 11th century with a rectangular presbytery, sacristy and a massive western tower [10]. The church is located on an elevated terrain and is surrounded by fortifications. Since its
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010
G Model CULHER-2877; No. of Pages 5
ARTICLE IN PRESS P. Brezina / Journal of Cultural Heritage xxx (2014) xxx–xxx
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Fig. 4. Graphs of relations of the rate of speech clarity (C50) values for the sound source positions S1 and S2. (a): Christian Reformed Church in Kalinˇciakovo; (b): St. Stephen-King Church in Nitra; (c): Our Lady Queen of Angels Church in Sádok.
creation, it has undergone many modifications and redevelopments, and the current research points to the presence of multiple styles (Romance, Gothic, Renaissance, Baroque and 20th century) [11]. In the 20th century, a number of church repairs took place (1937, 1958 and 1992). Since 2002 and thanks to the civic association Slovacia Incognita, extensive archaeological research has been taking place in order to restore the building [12]. The acoustic environment is greatly affected by a brick floor and a renovated wooden ceiling. The interior also has a stone pulpit, a wooden choir loft with no organ and a simple stone altar. 3. Research methodology In the premises of churches and temples, one of the most important acoustic parameters is the intelligibility and clarity of the speech. Among the most frequently measured two variables are the objective evaluation of speech intelligibility measured by Speech Transmission Index (STI) and the rate of speech clarity (C50). Since STI values are calculated using the modulation index m(F) based on the fact of reducing intelligibility by space reverberation and background noise, there was background noise detected while recording and it was taken into account in processing the research results. The STI values can be grouped into several categories representing the level of intelligibility [13] (Fig. 3). The resulting STI values are processed and presented according to the methodology of Soeta et al. [14] and they are presented as mean values of the modulation transfer functions of all frequencies and modulation frequencies, with the individual values being weighted for the male voice according to IEC 60268-16. The rate of speech clarity C50 is expressed in decibels (dB). The values above 0 dB present good speech intelligibility and the values below −7 dB stand for a not too suitable space for the speech [15]. The STI and C50 values were measured from the same positions of the sound source and the microphones, the location of which was based on the methodology of measuring the acoustics of churches by Martellotta et al. [16]. Furthermore, the measurement was based on the methodology described in the STN EN ISO 3382 standard [17]. All measurements were conducted when the spaces were unoccupied.
3.1. Positions of sound sources A sound source with sound radiation characteristics similar to human vocal tract characteristics was placed in all measured areas in two positions, which are intended for lecturing speech at 1.5 m above the ground. Fig. 2 shows church floor plans indicating the location of sound sources and microphones. In church (c), the position S1 was located at a distance of 1.5 m in front of the stone altar in the apse area and the second position S2 was in the stone pulpit area. In the church (a), the position S1 was at a distance of 1.5 m in front of the place where the altar used to be located and the second position S2 was in the pulpit area. Determining the appropriate positions of sound sources in church (b) was more complicated due to the fact that the church is currently rented to the Greek Catholic Church. The most significant factor affecting the location of sound sources was the presence of an iconostasis in the apse area. The position of the sound source S1 represents a central position at a distance of 1.5 m in front of the iconostasis. The position S2 represents the probable location of the ambo placement during the Roman Catholic liturgy. 3.2. Microphone positions In view of the dimensions of the churches, there were seven microphone positions in churches (a) and (b) and ten in church (c). One microphone position was always placed within the choir loft. The microphones were placed at a height of 1.2 m above ground level, which roughly corresponds to the seated listener’s ear level. For greater accuracy, ten averaged measurements were conducted in each microphone position using a calibrated microphone. The microphone positions are shown in Fig. 2. 4. Research evaluation The results of measurements are presented in two categories of graphs. The first category consists of graphs of the speech transmission index values (Fig. 3), showing all measured microphone
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010
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positions in relation to the positions of the sound source. The second category comprises the rate of speech clarity C50 graphs (Fig. 4), comparing the measured values of two positions of the sound source for each measured space. In all measured areas, the STI values show the most accentuated deviations at the first microphone positions. On balance, we can say that the scale of the measured values from both sound source positions in all of the measured churches fall into the category of satisfactory speech intelligibility. Comparison of the rate of speech clarity C50 shows better parameters in the sound source position S2 in each measured area. In church (b), this position is the place where the ambo was probably located in the past, and it can therefore be described as suitable for speech. The space of church (c) has, despite the relatively low measured values of C50 in the frequency range of 500 Hz to 1000 Hz, an acceptable level of clarity of the speech, in as much as the human ear is most sensitive in the range of 2000 Hz to 4000 Hz. In this range, the measured values are significantly higher. The total average of measurements of the rate of speech clarity C50 performed in the church (a) points to a level slightly below 0 dB, a level where it is possible to speak of an average level of clarity of the speech. A comparison of C50 values, however, shows a slightly greater degree of clarity of the speech when uttered from the pulpit area (S2). In order to achieve more accurate characteristics of measured spaces, more acoustic parameters must be mentioned which were measured during the field research (Fig. 2): • reverberation time measured in seconds (T20 and T30); • early decay time measured in seconds (EDT); • the centre of impulse response in milliseconds (Ts); 5. Conclusion The measured STI values indicate a satisfactory level of speech intelligibility in each of the measured areas. It is possible to conclude that the positions of the sound source (S) have no significant effect on the level of clarity and the largest differences can be observed from the first two microphone positions, while other positions do correlate to a large extent. Comparing the measurement results with the existing and published ones, only three churches were found with approximately the same volume and surface area, where similar measurements had been made. The first one is an unnamed church marked A in the above-mentioned study made by Soeta et al. (volume 1000 m3 ; STI mean values between 0.45 and 0.60), the second and the third one are churches in Switzerland [18] – Cheseaux (volume: 575 m3 ; STI mean value: 0.449) and Romanel (volume: 477 m3 ; STI mean value: 0.577). It is obvious that the STI values are comparable to those that were presented in this case study. Compared to bigger Romanesque churches – Lapa (volume: 11,423 m3 ; STI mean value: 0.38) or Grilos (volume: 14,497 m3 : STI mean value: 0.33) [19] – the space clarity level measured in this case study is better. Evaluation of the parameter of
5
speech clarity C50 appears to be more pronounced, wherein measurements show better values just at the location of the pulpits or ambos in each of the measured areas. It should also be noted that the evaluation of the speech clarity parameter C50 is rare in studies of a similar nature, as most of those studies are aimed at evaluating the music clarity parameter C80. Measuring the quality of intelligibility and clarity of the speech provides, along with other measurements of space acoustic parameters, a complete picture of the nature and usefulness of church buildings, and it also represents a certain form of storing information about the acoustics as a form of intangible cultural heritage. The presented research data is relevant for comparison with future similarly-oriented research in smaller Romanesque churches (volume in the range of 300 to 600 m3 ) which have previously been studied only minimally from an acoustic point of view. References [1] F. Gugliermetti, F. Bisegna, A. Monaco, Acoustical evolution of the Roman Theatre of Ostia, Building Acoustics 15 (2) (2008) 153–168. [2] E. Cirillo, F. Martellotta, Acoustics of Apulian Romanesque Churches: correlations between architectural and acoustic parameters, Building Acoustics 10 (1) (2003) 55–76. [3] G. Iannace, A. Trematerra, The rediscovery of Benevento Roman Theatre Acoustics, J. Cultur. Herit. (2013), http://dx.doi.org/10.1016/j.culher.2013.11.012. [4] P. Brezina, Acoustics of historic spaces as a form of intangible cultural heritage, Antiquity 87 (336) (2013) 574–580. ´ pramenova, ˇ [5] H. Zˇ aˇzová, Romanika v zrkadle písomnych Monumentorum Tutela 22 (2010) 370–372. ˇ ´ Kalinˇciakovo, http://www.apsida.sk/c/15/kalinciakovo, 2007. [6] S. Podolinsky, [7] Á. Szénassy, Felvidéki–Árpád-kori templomok lexikona, Komarnanske Tlaciarne, Komárno, 2002, pp. 63. ˇ Podolinsky, ´ Nitra-Párovce, http://www.apsida.sk/c/2511/nitra-parovce, [8] S. 2009. [9] Website of Greek Catholic Church in Nitra, http://www.grkatnr. sk/index.php/chram.html, 2009. [10] J. Lukaˇcka, Historické súvislosti vzniku a funkcie stredovekého farského Kostola Panny Márie v Klátovej Novej Vsi - Sádku, Monumentorum Tutela 22 (2010) 73–82. ´ [11] M. Bóna, M. Mikuláˇs, Vysledky architektonicko-historického a umelecko´ historického vyskumu Kostola Panny Márie Král’ovnej anjelov v Klátovej Novej Vsi–ˇcast’ Sádok, Monumentorum Tutela 22 (2010) 83–98. ˇ [12] M. Bóna, M. Mikuláˇs, História kostola v sádku v archívnych pramenoch, http://incognita.eu/kostolik v sadku.html, 2011. [13] International Standard, IEC 60268-16 Sound System Equipment. Part 16: objective rating of speech intelligibility by speech transmission index, International Electrotechnical Commission, Geneva, 2011. [14] Y. Soeta, K. Ito, R. Shimokura, S. Sato, T. Ohsawa, Y. Ando, Effects of sound source location and direction on acoustic parameters in Japanese churches, J. Acoustical Soc. Am. 131 (2) (2012) 1206–1220. [15] A. Czerwinski, Z. Dziechciowski, Evaluation of acoustical properties of an auditorium after a modernisation program, Acta Physica Polonica 125 (2014) 71–76. [16] F. Martellotta, E. Cirillo, A. Carbonari, P. Ricciardi, Guidelines for acoustical measurements in churches, Appl. Acoustics 70 (2009) 378–388. [17] SUTN Slovak Office of standards, metrology and testing, STN EN ISO 3382-1 Acoustics. Measurement of room acoustic parameters. Part 1: performance spaces, Slovak Office of Standards, Metrology and Testing, Bratislava, 2010. [18] V. Desarnaulds, A.P.O. Carvalho, G. Monay, Church acoustics and the influence of occupancy, Building Acoustics 9 (2002) 29–47. [19] A.P.O. Carvalho, M.M.F. Lencastre, Catholic churches, sound-reinforcement systems and RASTI, Int. J. Acoustics Vibration 5 (2000) 7–14.
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010
ARTICLE IN PRESS Journal of Cultural Heritage xxx (2014) xxx–xxx
Available online at
ScienceDirect www.sciencedirect.com
Case study
Measurement of intelligibility and clarity of the speech in romanesque churches Pavol Brezina ∗ Department of Music, Constantine the Philosopher University in Nitra, Tr. A. Hlinku 1, 94901 Nitra, Slovakia
a r t i c l e
i n f o
Article history: Received 1st March 2014 Accepted 19 June 2014 Available online xxx Keywords: Acoustics Romanesque churches Cultural heritage Speech intelligibility Architecture
a b s t r a c t Intelligibility and clarity of the speech are important acoustic parameters of sacred spaces, such as churches and temples. The study focuses on the description of the acoustic characteristics of Romanesque churches with a matroneum from the 10th up to the 12th century and compares the results of measurements taken from different positions intended for speech recitation. From the complex acoustic research, the case study focuses on the presentation of the results of measurements of clarity and intelligibility of the speech via acoustic field research. The research objects are three important Romanesque churches with a matroneum in Slovakia–Christian Reformed Church in Kalinˇciakovo, St. Stephen-King Church in Nitra and the Our Lady Queen of Angels Church in Sádok. The aim of the research is to highlight not just the differences but also the commonalities of the selected acoustic parameters of these churches. © 2014 Elsevier Masson SAS. All rights reserved.
1. Introduction The Romanesque cultural heritage is one of the primary research objects in archeology, history, restoration, art and architecture. Its extensive archaeological and historical-artistic research has recently started to increasingly encompass acoustic research, too. Firstly, it comes to describing the basic acoustic properties of the space by measuring various acoustic parameters. From the Romanesque period, among the most frequently studied spaces are ancient theatres [1] and sacred buildings [2]. In addition to the characteristics of the acoustic properties, the research also deals with virtual acoustic environment simulation, and some of the studies are devoted to the specific research of historical buildings in terms of human speech intelligibility and musical interpretation [3]. The possibility of keeping such virtual models as intangible cultural heritage has also begun to be discussed [4]. This case study is devoted to the research of intelligibility of the speech in smaller Romanesque churches with a matroneum. In churches, the speech is currently most frequently uttered from the area in front of the altar, but in the past the specific raised points, such as the pulpit, were the dominant place, especially during sermons. The measurement and comparison of the intelligibility of speeches given from selected places in the church compare the level of functionality of these places via a new scientific perspective. The primary objective of this case
∗ Tel.: +421904247459. E-mail addresses: [email protected], [email protected]
study is to document the important acoustic parameters of smaller Romanesque churches, which are important historical monuments of Central Europe. Similar research has not as yet been conducted. This is also research which documents the acoustics of important cultural sites as a form of intangible cultural heritage.
2. Research objects The selected research objects (Fig. 1) were the oldest preserved Romanesque churches in Slovakia–Christian Reformed Church in Kalinˇciakovo (a), St. Stephen-King Church in Nitra (b) and the Our Lady Queen of Angels Church in Sádok (c). The history of the Christian Reformed Church (volume: 272 m3 ) in Kalinˇciakovo dates back to when it was built in the first half of the 12th century. It is now one of the most important Romanesque buildings in Slovakia. Originally, the Roman Catholic Church dedicated to St. Anne was violently taken by the Calvinists in 1655 [5]. Reconstruction works on site were carried out in 1932, 1956 and 2003 [6]. From a construction point of view, the church consists of a Romanesque apse and a nave. St. Stephen-King Church in Nitra (volume: 316.8 m3 ), located in the neighbourhood of Párovce, is a characteristic singlenave building with a matroneum and a semicircular apse [7]. The church stood in this place probably in the 10th century. In the 11th and 12th century, it was rebuilt in the Romanesque style [8]. Until 1992, the church was seldom used and fell into disrepair. The change came on 1st September 1992, when it was rented to the Greek Catholic Church [9]. Several changes then took place inside the church, the most striking one being the space adaptation for
http://dx.doi.org/10.1016/j.culher.2014.06.010 1296-2074/© 2014 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010
G Model CULHER-2877; No. of Pages 5 2
ARTICLE IN PRESS P. Brezina / Journal of Cultural Heritage xxx (2014) xxx–xxx
Fig. 1. Exterior and interior photos of churches. (a): Christian Reformed Church in Kalinˇciakovo; (b): St. Stephen-King Church in Nitra; (c): Our Lady Queen of Angels Church in Sádok.
Fig. 2. Part A: church floor plans indicating the location of sound sources (S) and microphone positions (p). (a): Christian Reformed Church in Kalinˇciakovo; (b): St. StephenKing Church in Nitra; (c): Our Lady Queen of Angels Church in Sádok. Part B: reverbation time (T30, T20), early decay time (EDT) and the centre of impulse response (Ts) measured values for individual churches.
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010
G Model CULHER-2877; No. of Pages 5
ARTICLE IN PRESS P. Brezina / Journal of Cultural Heritage xxx (2014) xxx–xxx
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Fig. 3. Part A: graphs of relations of speech transmission index (STI) values for the sound source positions S1 and S2 . (a): Christian Reformed Church in Kalinˇciakovo; (b): St. Stephen-King Church in Nitra; (c): Our Lady Queen of Angels Church in Sádok. Part B: subjective speech intelligibility assessment scale and range of STI measured values for individual churches.
Greek Catholic worship and the placement of an iconostasis in the area of the apse. The choir loft of the church is well preserved and no organ is present in it. Our Lady Queen of Angels Church in Sádok (volume: 635 m3 ) is an important architectural cultural monument
in Slovakia. It is a one-nave building dating to the period of the second half of the 11th century with a rectangular presbytery, sacristy and a massive western tower [10]. The church is located on an elevated terrain and is surrounded by fortifications. Since its
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010
G Model CULHER-2877; No. of Pages 5
ARTICLE IN PRESS P. Brezina / Journal of Cultural Heritage xxx (2014) xxx–xxx
4
Fig. 4. Graphs of relations of the rate of speech clarity (C50) values for the sound source positions S1 and S2. (a): Christian Reformed Church in Kalinˇciakovo; (b): St. Stephen-King Church in Nitra; (c): Our Lady Queen of Angels Church in Sádok.
creation, it has undergone many modifications and redevelopments, and the current research points to the presence of multiple styles (Romance, Gothic, Renaissance, Baroque and 20th century) [11]. In the 20th century, a number of church repairs took place (1937, 1958 and 1992). Since 2002 and thanks to the civic association Slovacia Incognita, extensive archaeological research has been taking place in order to restore the building [12]. The acoustic environment is greatly affected by a brick floor and a renovated wooden ceiling. The interior also has a stone pulpit, a wooden choir loft with no organ and a simple stone altar. 3. Research methodology In the premises of churches and temples, one of the most important acoustic parameters is the intelligibility and clarity of the speech. Among the most frequently measured two variables are the objective evaluation of speech intelligibility measured by Speech Transmission Index (STI) and the rate of speech clarity (C50). Since STI values are calculated using the modulation index m(F) based on the fact of reducing intelligibility by space reverberation and background noise, there was background noise detected while recording and it was taken into account in processing the research results. The STI values can be grouped into several categories representing the level of intelligibility [13] (Fig. 3). The resulting STI values are processed and presented according to the methodology of Soeta et al. [14] and they are presented as mean values of the modulation transfer functions of all frequencies and modulation frequencies, with the individual values being weighted for the male voice according to IEC 60268-16. The rate of speech clarity C50 is expressed in decibels (dB). The values above 0 dB present good speech intelligibility and the values below −7 dB stand for a not too suitable space for the speech [15]. The STI and C50 values were measured from the same positions of the sound source and the microphones, the location of which was based on the methodology of measuring the acoustics of churches by Martellotta et al. [16]. Furthermore, the measurement was based on the methodology described in the STN EN ISO 3382 standard [17]. All measurements were conducted when the spaces were unoccupied.
3.1. Positions of sound sources A sound source with sound radiation characteristics similar to human vocal tract characteristics was placed in all measured areas in two positions, which are intended for lecturing speech at 1.5 m above the ground. Fig. 2 shows church floor plans indicating the location of sound sources and microphones. In church (c), the position S1 was located at a distance of 1.5 m in front of the stone altar in the apse area and the second position S2 was in the stone pulpit area. In the church (a), the position S1 was at a distance of 1.5 m in front of the place where the altar used to be located and the second position S2 was in the pulpit area. Determining the appropriate positions of sound sources in church (b) was more complicated due to the fact that the church is currently rented to the Greek Catholic Church. The most significant factor affecting the location of sound sources was the presence of an iconostasis in the apse area. The position of the sound source S1 represents a central position at a distance of 1.5 m in front of the iconostasis. The position S2 represents the probable location of the ambo placement during the Roman Catholic liturgy. 3.2. Microphone positions In view of the dimensions of the churches, there were seven microphone positions in churches (a) and (b) and ten in church (c). One microphone position was always placed within the choir loft. The microphones were placed at a height of 1.2 m above ground level, which roughly corresponds to the seated listener’s ear level. For greater accuracy, ten averaged measurements were conducted in each microphone position using a calibrated microphone. The microphone positions are shown in Fig. 2. 4. Research evaluation The results of measurements are presented in two categories of graphs. The first category consists of graphs of the speech transmission index values (Fig. 3), showing all measured microphone
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010
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ARTICLE IN PRESS P. Brezina / Journal of Cultural Heritage xxx (2014) xxx–xxx
positions in relation to the positions of the sound source. The second category comprises the rate of speech clarity C50 graphs (Fig. 4), comparing the measured values of two positions of the sound source for each measured space. In all measured areas, the STI values show the most accentuated deviations at the first microphone positions. On balance, we can say that the scale of the measured values from both sound source positions in all of the measured churches fall into the category of satisfactory speech intelligibility. Comparison of the rate of speech clarity C50 shows better parameters in the sound source position S2 in each measured area. In church (b), this position is the place where the ambo was probably located in the past, and it can therefore be described as suitable for speech. The space of church (c) has, despite the relatively low measured values of C50 in the frequency range of 500 Hz to 1000 Hz, an acceptable level of clarity of the speech, in as much as the human ear is most sensitive in the range of 2000 Hz to 4000 Hz. In this range, the measured values are significantly higher. The total average of measurements of the rate of speech clarity C50 performed in the church (a) points to a level slightly below 0 dB, a level where it is possible to speak of an average level of clarity of the speech. A comparison of C50 values, however, shows a slightly greater degree of clarity of the speech when uttered from the pulpit area (S2). In order to achieve more accurate characteristics of measured spaces, more acoustic parameters must be mentioned which were measured during the field research (Fig. 2): • reverberation time measured in seconds (T20 and T30); • early decay time measured in seconds (EDT); • the centre of impulse response in milliseconds (Ts); 5. Conclusion The measured STI values indicate a satisfactory level of speech intelligibility in each of the measured areas. It is possible to conclude that the positions of the sound source (S) have no significant effect on the level of clarity and the largest differences can be observed from the first two microphone positions, while other positions do correlate to a large extent. Comparing the measurement results with the existing and published ones, only three churches were found with approximately the same volume and surface area, where similar measurements had been made. The first one is an unnamed church marked A in the above-mentioned study made by Soeta et al. (volume 1000 m3 ; STI mean values between 0.45 and 0.60), the second and the third one are churches in Switzerland [18] – Cheseaux (volume: 575 m3 ; STI mean value: 0.449) and Romanel (volume: 477 m3 ; STI mean value: 0.577). It is obvious that the STI values are comparable to those that were presented in this case study. Compared to bigger Romanesque churches – Lapa (volume: 11,423 m3 ; STI mean value: 0.38) or Grilos (volume: 14,497 m3 : STI mean value: 0.33) [19] – the space clarity level measured in this case study is better. Evaluation of the parameter of
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speech clarity C50 appears to be more pronounced, wherein measurements show better values just at the location of the pulpits or ambos in each of the measured areas. It should also be noted that the evaluation of the speech clarity parameter C50 is rare in studies of a similar nature, as most of those studies are aimed at evaluating the music clarity parameter C80. Measuring the quality of intelligibility and clarity of the speech provides, along with other measurements of space acoustic parameters, a complete picture of the nature and usefulness of church buildings, and it also represents a certain form of storing information about the acoustics as a form of intangible cultural heritage. The presented research data is relevant for comparison with future similarly-oriented research in smaller Romanesque churches (volume in the range of 300 to 600 m3 ) which have previously been studied only minimally from an acoustic point of view. References [1] F. Gugliermetti, F. Bisegna, A. Monaco, Acoustical evolution of the Roman Theatre of Ostia, Building Acoustics 15 (2) (2008) 153–168. [2] E. Cirillo, F. Martellotta, Acoustics of Apulian Romanesque Churches: correlations between architectural and acoustic parameters, Building Acoustics 10 (1) (2003) 55–76. [3] G. Iannace, A. Trematerra, The rediscovery of Benevento Roman Theatre Acoustics, J. Cultur. Herit. (2013), http://dx.doi.org/10.1016/j.culher.2013.11.012. [4] P. Brezina, Acoustics of historic spaces as a form of intangible cultural heritage, Antiquity 87 (336) (2013) 574–580. ´ pramenova, ˇ [5] H. Zˇ aˇzová, Romanika v zrkadle písomnych Monumentorum Tutela 22 (2010) 370–372. ˇ ´ Kalinˇciakovo, http://www.apsida.sk/c/15/kalinciakovo, 2007. [6] S. Podolinsky, [7] Á. Szénassy, Felvidéki–Árpád-kori templomok lexikona, Komarnanske Tlaciarne, Komárno, 2002, pp. 63. ˇ Podolinsky, ´ Nitra-Párovce, http://www.apsida.sk/c/2511/nitra-parovce, [8] S. 2009. [9] Website of Greek Catholic Church in Nitra, http://www.grkatnr. sk/index.php/chram.html, 2009. [10] J. Lukaˇcka, Historické súvislosti vzniku a funkcie stredovekého farského Kostola Panny Márie v Klátovej Novej Vsi - Sádku, Monumentorum Tutela 22 (2010) 73–82. ´ [11] M. Bóna, M. Mikuláˇs, Vysledky architektonicko-historického a umelecko´ historického vyskumu Kostola Panny Márie Král’ovnej anjelov v Klátovej Novej Vsi–ˇcast’ Sádok, Monumentorum Tutela 22 (2010) 83–98. ˇ [12] M. Bóna, M. Mikuláˇs, História kostola v sádku v archívnych pramenoch, http://incognita.eu/kostolik v sadku.html, 2011. [13] International Standard, IEC 60268-16 Sound System Equipment. Part 16: objective rating of speech intelligibility by speech transmission index, International Electrotechnical Commission, Geneva, 2011. [14] Y. Soeta, K. Ito, R. Shimokura, S. Sato, T. Ohsawa, Y. Ando, Effects of sound source location and direction on acoustic parameters in Japanese churches, J. Acoustical Soc. Am. 131 (2) (2012) 1206–1220. [15] A. Czerwinski, Z. Dziechciowski, Evaluation of acoustical properties of an auditorium after a modernisation program, Acta Physica Polonica 125 (2014) 71–76. [16] F. Martellotta, E. Cirillo, A. Carbonari, P. Ricciardi, Guidelines for acoustical measurements in churches, Appl. Acoustics 70 (2009) 378–388. [17] SUTN Slovak Office of standards, metrology and testing, STN EN ISO 3382-1 Acoustics. Measurement of room acoustic parameters. Part 1: performance spaces, Slovak Office of Standards, Metrology and Testing, Bratislava, 2010. [18] V. Desarnaulds, A.P.O. Carvalho, G. Monay, Church acoustics and the influence of occupancy, Building Acoustics 9 (2002) 29–47. [19] A.P.O. Carvalho, M.M.F. Lencastre, Catholic churches, sound-reinforcement systems and RASTI, Int. J. Acoustics Vibration 5 (2000) 7–14.
Please cite this article in press as: P. Brezina, Measurement of intelligibility and clarity of the speech in romanesque churches, Journal of Cultural Heritage (2014), http://dx.doi.org/10.1016/j.culher.2014.06.010