In some spaces such as concert-opera halls and religious buildings, acoustical perception is as much as and sometimes more important than visual perception. Mosques and churches are of those rare buildings that affect human perception almost equally both from acoustical and visual point of views. In other words, as the fundamental aims of religious buildings are to make the attendees feel themselves close to God and to direct their thoughts and feelings towards worshipping, acoustical perception is highly significant within these spaces.
Conservation and restoration of the architectural heritage were
restricted with material means until now. However, it is obvious that,
preserving architectural heritage should include preserving of the acoustical
heritage, especially for the spaces
having acoustical importance. The acoustics of ancient places of worship, like
mosques and churches, that is the peculiarities of the listening attributes
experienced by the listeners inside these marvellous places, is a fundamental
aspect for the full understanding of the historical and social development of
vast communities.
In this
context, a research project named “Conservation of the Acoustical Heritage by
the Revival and Identification of the Sinan’s Mosques’ Acoustics – CAHRISMA”
has been designed and submitted to the EC Fifth Framework INCO MED programme.
The participants of the project are Yıldız Technical University
(Turkey), Technical University of Denmark (Denmark), Universita degli Studi di
Ferrara (Italy), Ecole Polytechnique Fédérale de Lausanne (Switzerland),
University of Geneva (Switzerland), Institut National de Recherche sur les
Transports et leur Sécurité (France) and University of Malta (Malta).
Main objective of the CAHRISMA project which took start at the beginning of the February 2000, is to innovate the concept of “Hybrid Architectural Heritage”. Hybrid Architectural Heritage is a new way of identification that covers acoustical characteristics besides visual peculiarities. It states that, for the spaces, having acoustical importance, “architectural heritage concept” should be upgraded covering acoustical and visual properties. The effects of this improvement will reflect to actual implementation of conservation and restoration.
GOALS AND OBJECTIVES OF THE
CAHRISMA PROJECT
The basic objective of the
CAHRISMA project is to innovate and implement the concept of “Hybrid
Architectural Heritage”, in the field of conservation and restoration. Sinan’s
Mosques and Byzantine Chruches have been selected as the buildings to be worked
on at this study. (Architect Sinan “1492?-1588?” has a place on the history of
architecture as a style – creating artist and he was highly influenced by
Byzantine architecture) The reason of this choice is that, although they are
well-known of their acoustical qualities besides others, few work has been done
to identify and conserve their acoustical
peculiarities. The study will cover the identification and revival as well as
the restoration and conservation of the acoustical heritage (at the virtual
environment) of the monuments such as Süleymaniye Mosque and Hagia Sophia
Church. At this project, not only the architectural work will be reconstructed
virtually, but the life inside will also be recreated. In order to simulate the
realistic effects, virtual humans will be simulated and reproduced. Specific
scientific and technological goals of
CAHRISMA project are summarised as follows;
·
Identification of the recent and initial acoustical
peculiarities of the Sinan’s mosques and Byzantine churches, by acoustical
measurements and computer aided modelling tools.
·
Evaluation of psycho-acoustical and subjective
characteristics of these worship
spaces.
·
Integration of acoustical and visual virtual
environments into an interactive 3D real-time system.
·
Creation of an integrated real-time system for CD-ROM
of 3D architectural models with realistic virtual humans.
·
Comparison of the
mosques and churches acoustics and review of the acoustical influence of
Byzantine churches on Sinan’s mosques.
·
Determination of the optimum acoustical conditions for
mosques by the comparison of subjective parameters obtained from psycho-acoustical surveys with the objective
parameters obtained from measurements and calculations.
·
Conservation and restoration of the selected monuments
architectural heritage (acoustical and visual) in a virtual environment.
By the achievement of the objectives and goals of this wide frame
research, conceptual and practical innovations and improvements in the fields
of acoustics, lighting, simulation technologies, architecture, conservation -
restoration and tourism will be created. Besides the conservation of the
architectural heritage and the development in the related scientific fields,
this project will contribute to the increase of interest for historical
monuments and enhance touristical
curiosity, attracting attentions to a
different feature.
PROJECT METHODOLOGY
Increased interdisciplinary and trans-disciplinary
features should be used at the identification and conservation of the “Hybrid
Architectural Heritage”. The objective described above is reachable by the
co-ordination of architecture, acoustics, psycho-acoustics and computer sciences. A methodology that will
have apparent benefits both in identification and conservation fields, will be
developed in order to transport the “Hybrid Architectural Heritage” into
virtual environment. This methodology will cover the combination of visual and
acoustical features of the architectural spaces in interactive 3D virtual
environments. By the utilisation of the mentioned methodology, for the
situations where architectural conservation and restoration are not available,
virtual conservation and restoration will have been provided. The methodology
of the project consists of the
following steps;
1. Acoustical
identification and evaluation
·
Objective identification and evaluation (measurements,
calculations)
·
Subjective identification and evaluation (psycho-acoustical
surveys)
2. Creation
of the Virtual Environment
·
Visual simulation (simulation of the spaces, simulation of
the humans)
·
Acoustical simulation
·
Combined 3D real time simulation
3. Virtual
revival and recovery
The flow chart of the methodology
described briefly above, is shown at Figure 1. The project has been designed of
ten work packages in order to reach the objectives and goals described above.
Work packages of the project and their short explanations are given in Table 1.
The participants of each work package are shown at Figure 1; first participants
(written in bold) are the responsibles of work packages.
Figure 1. Flow Chart of the
project.
Psycho-acoustical Survey INRETS UNIFE YTU
WP7
At first, Sinan’s mosques
peculiarities as architectural style, size and other properties which could affect acoustical behaviour of spaces,
will be researched and evaluated. Then mosques to work on at this project will
be selected. Selected mosques will be at adequate quantity and quality to
illustrate general peculiarities of Sinan’s architecture. Meanwhile, a similar
work will be held on Byzantine churches that are known to have had affected
Sinan’s work, so their acoustics as well. Therefore, worship spaces that will
be used in that project will be determined. Afterwards, all the reachable
plans, projects, data on materials and technologies about the selected works
will be gathered. Those will be the input data base, that all participants can
utilise when necessary.
Table
1. Work packages and short explanations
WP
no
|
WP
Name
|
WP Short Explanation |
WP1
|
Project Management |
Project management; scientific,
administrative and financial co-ordination between participants and/or
Commission |
WP2
|
Taxonomy of mosques &
|
Taxonomy
of Sinan’s mosques & Byzantine churches |
|
|
Churches |
Selection
of worship spaces and research on acoustical activities |
WP3
|
Acoustical Measurements
|
Measurements of room acoustical behavior of |
|
|
|
selected Sinan’s mosques and Byzantine
churches |
|
WP4 |
Acoustical Simulations |
Computer simulation of acoustical behavior of |
|
|
|
selected Sinan’s mosques and Byzantine
churches |
|
WP5 |
Real-time |
Virtual real time visualization of the
architectural works with |
|
|
Visualization |
ınhabitants |
|
WP6 |
Integration & development of Hybrid
Architectural Heritage System |
Integration of visual and
acoustical computer models into a synchronized real-time virtual environment
for content production and architectural evaluations
|
|
|
Psycho-acoustical
|
Psycho-acoustical surveys for
identification of subjective
|
WP7
|
Surveys
|
acoustical parameters of sound fields inside
mosques and churches |
|
WP8 |
Virtual Conservation. & |
Development of Virtual Restoration &
Virtual Conservation Systems for selected works |
|
|
Virtual Restoration |
Evaluation of acoustical parameters and determination of optimum acoustical
conditions |
|
WP9
|
Comparison &
Evaluation
|
Comparison of the selected mosques and
churches acoustics in order to determine the influence of churches on mosques
and Evaluation of mosques’ and churches’ acoustical |
|
|
of mosques and churches
|
qualities in order to improve the modern
architectural design tools for halls with domes |
WP10
|
Evaluation
&Dissemination
|
Evaluation
and Dissemination of the project |
Measurement methodologies will be
determined so as to permit and facilitate comparison between mosques and
churches. After the determination of measurement methodologies taking into
consideration mosques and churches peculiarities, room acoustical measurements
will be realised by two different groups for comparative reasons. The
measurements will be made basicly according to ISO 3382:1997 and different
parameters will be derived from reverberation time measurements. In addition to
RT measurements, Speech Transmission Index will also be measured. Thus, current
peculiarities of selected spaces for music and speech activities will have been evaluated. With a sufficient number of source and
receiver positions the results will characterise the acoustical behaviour of
the investigated rooms. The results of
different groups will be compared and statistically evaluated.
Room
acoustics programs for computing simulation of the acoustical behaviour of
selected works will be used to determine and evaluate worship spaces. Computer
simulations will be compared with the measuring results in order to verify the
simulation models. Then the computer simulations will be used to analyse the
influence of a number of changes of surface materials, including estimated
absorption properties of ancient materials. The comparisons will be made in two
ways; objectively by the comparison of the calculated room acoustical
parameters, and subjectively (where available) by listening to simulated sounds
using the auralisation techniques.
Human’s
acoustical interpretation and understanding of halls are deeply affected from
visual, social and psychological
factors. That’s why selected works will be visualised in real time and 3D, so
as to create a synchronised real time realistic system. Besides the modelling of the ancient environments, simulation of people
and their motion inside the mosque and synchronisation
with sounds will constitute major parts of this work. Simulation of human
crowds for populating virtual worlds will
provide, a more realistic sense of virtual group presence.
Also, in the context of interaction, a multi-modal
interface will be investigated in order to guide crowds including cyberglove,
speech recognition and sound generator, and it will be managed between the different applications, as
well as the virtual human animation. As main challenge of communication between
multi-modal interfaces and virtual crowds, the issues such as analysing the
various levels of sound perception
which can occur depending on the
people location and distance related to sound source, are of special
interest. On the other hand, the number of occupants and the way they are
dressed affect total absorption of the spaces and this effect is perceived by
people. For the creation of the realistic and authentic environments, virtual
humans should have to simulated and dressed properly. After making a study of
the human bodies sizes representing a population, computer geometry algorithms
that will allow create bodies of different sizes will be developed. A complete
population will be created from a few different individuals, using a 3D
morphing methodology. A methodology for automatic texturing of the body in
order to give the impression, people are being dressed will also developed.
Visual and acoustical
combination in 3D and real time system which is the main challenge of this
study will be obtained by the trans-disciplinary work of four groups. In order
to generate an inter-active CD-ROM, all the techniques and databases created in
the research will be integrated. This CD-ROM will allow user to interact with
the 3D architectural design and hear the sounds specific to this 3D
architecture created through the acoustical computer models. Thus environments
that person who use the final product feel that he/she is in the worship space;
walk through crowds or sit at a place and hear realistic sounds will be
created. Those virtual environments will be utilised both in virtual
restoration and virtual conservation.
Since the main domain of this work is highly related with human comfort and almost no statistical results exist on this area, a wide range of subjective evaluations will be held. Subjective evaluations, namely surveys (site and laboratory), will include two aspects; site surveys, for psycho-acoustical evaluation of the sound quality, the interviews will be made on two subgroups (the users and the visitors), laboratory surveys, for the evaluation of different aspects of acoustical quality, a different subgroup and several recorded sound samples will be utilised. A comparison of the two sets of survey results will then be used, both for the determination of the specific acoustical qualities of the environments and the development of predictive modelling tools.
By the
interdisciplinary work of the groups worked on subjective and objective
evaluations, optimum acoustical conditions for mosques and churches will be
developed. Therefore knowledge that could be used on the design of worship
spaces will be available. On the other hand, selected architectural spaces
virtual restoration and virtual conservation will be held by the combination of
ancient and initial audio-visual peculiarities.
For the
designation of the Byzantine churches acoustical effects on Sinan’s mosques,
accumulated objective and subjective data will be compared and research on the
proofs of mentioned effect will be done. For the utilisation of knowledge in
the current applications, another interdisciplinary work will be held. By this
work for the halls having concave surfaces, especially for halls with dome, establishment of data sets
to be used on the acoustical design will be targeted.
Current
state of the project
The project has begun recently,
at 01 February 2000. First meeting was held at Yıldız Technical
University in Istanbul, by the full participation of the partners. First
sequence of measurements will be done at June 2000. As all teams need the data
about the places to work on, YTU has begun to work on Sinan’s Mosques’ and Byzantine
Churches’. Kadırga Sokullu Mehmet Pacha Mosque and SS of Bacchus Church
(now used as a mosque called Little Hagia Sofia) have been selected as the
monuments that will be studied initially and started the data collection of
these buildings. At Figure 2., the plan and section of Kadırga Sokullu
Mehmet Pacha Mosque can be seen. Project teams are going on the preparation
about their parts.
Figure
2 Isometric projection, longitudinal section and plan (Encyclopedia ofWorld Architecture)
CONCLUSION
Main objectives of this research are identification, revival and conservation of architectural heritage in a new way. Objective and subjective evaluations and audio-visual reconstruction of Sinan’s Mosques and Byzantine Churches in real-time 3D virtual environments are the basic approaches to reach the goals of the project. Virtual restoration, virtual conservation, determination of different significant acoustical effects will be the main results. By means of this wide frame research, conceptual and practical innovations will be created in the fields of acoustics, architecture and simulation technologies.
By the application of the concept and techniques utilised in this project, humanity will protect and attend to an important and different part of his past. The Research Project CAHRISMA, will emphasise the role of Euro-Mediterranean Partnership within the international scientific field, and will undertake an important support to the advertisement of marvellous work of arts.
ACKNOWLEDGEMENTS
This study is being supported by the European Commission, within the “Confirming of International Role of Community Research – INCO MED” specific programme of the Fifth Framework.
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