l`acustica per il patrimonio culturale, tra diagnostica e spazi sonori

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L’ACUSTICA AL SERVIZIO DELLA CONSERVAZIONE DEL PATRIMONIO STORICO
La ricerca per l’innovazione della Tutela
Casa dell’Architettura, 10 dicembre 2014
L’ACUSTICA PER IL PATRIMONIO CULTURALE,
TRA DIAGNOSTICA E SPAZI SONORI
Paola CALICCHIA
CONSIGLIO NAZIONALE DELLE RICERCHE
Istituto di Acustica e Sensoristica “O. M. Corbino”
IDASC, www.idasc.cnr.it
[email protected]
Acoustical Methods for Non-Destructive Evaluation
ACoustic Energy Absorption Diagnostic Device
Scanning Acoustic Microscopy
Innovative Acoustic Sources: the Parametric Acoustic Array
Exhibition Spaces
and Story Tellers
Reconstruction of Historical Soundscapes
Hearing History
Conclusion
P. Calicchia 10/12/2014
Acoustical Methods for Non-Destructive Evaluation
ACoustic Energy Absorption Diagnostic Device
Scanning Acoustic Microscopy
The methods realizes
Acoustic Absorption Maps
Revealing detachments in
multilayer structures
FRESCOES – GLAZED CERAMIC TILES – PANEL PAINTINGS
CHURCH OF SANTA PASSERA
(ROME)
DEDICATED TO ABBÀS CYRUS:
DECEMBER 2001:
FRESCOES IN THE UPPER LEVEL CHURCH
upper level church (XIII a.C.)
lower level church (V a.C.)
hypogeous crypt (II - III a.C.);
CASA VASARI (FLORENCE)
Main Hall - BORGO SANTA CROCE (mid XVI century);
DECEMBER 2002:
THE ARCHITECT ANGEL
MADRE DE DEUS CONVENT (LISBON)
PORTUGUESE NATIONAL TILE MUSEUM
(NMAz, XVI cent.);
JULY 2009:
AZULEJO PANELS
ORATORIO OF SAN ROCCO PADUA
(mid XVI century);
MARCH 2011:
AI VS IR THERMO
Traditional analysis and Restoration
IR Thermography on frescoes
RWS S.r.l.
CNR - Construction Technologies Institute
Characterization of wall painting and
polychromy of the stucco altarpiece
Acoustic Imaging on frescoes
CNR - Institute of Inorganic Chemistry and
CNR – Institute of Acoustics and Sensors
of the Surface
ANNUNCIAZIONE
BY BENOZZO GOZZOLI (mid XV century);
MAY 2011:
PANEL PAINTING
STRADA NUOVA MUSEUMS (GENOA)
PALAZZO BIANCO GALLERY,
VENUS AND MARS BY RUBENS
NOVEMBER 2013:
PANEL PAINTING
The acoustic imaging technique
mass - air spring system
The Acoustic Energy Absorption Diagnostic Device reveals
sub-surface cavities
behaving as a selective acoustic absorber (mass - air spring system)
f0 
1
2
kair
c
 0
M
2
0
 S td
fundamental resonance frequency
in multilayer structures by measuring, on site, the acoustic absorption coefficient
extracting the impulse response h(t-t) of the analysed surface
and scanning the surface using a non contact setup
For each analysed point the result is expressed in terms of:
the amount of total reflected energy Σi
the absorption percentage ABS%
with respect to the most reflecting point ΣR
The resulting images can be also analysed in the frequency domain
The Context: Experimentation - Participation
In the Strada Nuova Museums, one of the major oil
paintings hosted in Palazzo Bianco Gallery, Venus and
Mars by Rubens, was analysed on site in its standard
location, for identifying its current state of conservation
after a number of restoration interventions and the
installation of controlled microclimate
(http://www.museidigenova.it)
... involving the visitors during usual museum exhibition time:
an opportunity to transmit an extended knowledge regarding
both the cultural patrimony and the scientific advancement in
the conservation process
A new form of art fruition
Art and Science
in a field experimentation participated by both the professionals of the
CH domain and the visitors
... promoting a new form of art fruition, not separated from the
diagnostic activity or the conservation process, offering to anyone a
deeper interaction with the artworks
As the value of such masterpieces resides
in the ability to penetrate history,
the employment of scientific tools is able
to penetrate their tangible aspects,
letting these objects become fascinating story tellers that unveil
the hidden tracks that time has left on them
13
Venus and Mars by Pieter Paul Rubens (1632-1635)
Initially inventoried as “Lansquenet with his Sweetheart”
(Corpus Rubenianum Ludwig Burchard)
and only recently in terms of mythological subject
(Cordaro et al., ICR,1985)
oil on panel
oak substrate
142 × 133 cm2
thinned (3.5 mm)
heavily cradled
The support presents four horizontal boards and a vertical one
having grain running normal to the first; the arrangement of the
boards thus denotes a high sensitivity to possible change of the
environmental parameters.
Venus and Mars by Pieter Paul Rubens (1632-1635)
Reverse with the cradle structures
Restoration interventions: between 1909 and 1939 only partial
restorations are carried out. The major interventions are later:
1952-55 – the chestnut cradle is removed, disclosing the actual
chestnut wood
arrangement of the support. Butterfly inserts and a new oak
up to 1951
wood structure are placed. Surface conservation is
accomplished.
1965 – constraints by the new cradle are present, substituted by
oak wood
a third one in pitch pine, guaranteeing independent movements
1952-55
of the vertical board with respect to the other ones.
1981 – relative humidity as low as 23% is revealed in some
rooms of the Gallery.
1981-84 – restoration realized by the Istituto Centrale del
pitch pine wood
Restauro. The substrate is treated for infestation (gassing) while
1965-66
the cradle is left unchanged. Although it is not completely
adequate, it is considered in equilibrium with the thinned panel,
and the risks due to its displacement are avoided. Surface
conservation is accomplished.
The experimental results
Measuring conditions: T = 22°C, RH = 56%
Wide band signal: (4 – 16)kHz
Analysed area: (1.36 × 1.1) m2
15207 analysed points
Repeatability test on a small portion,
compared with results from laboratory test
Post-processing to obtain a suitable accuracy
(i distribution with s equal to 6%)
Frequency resolved acoustic images
(the frequency is expressed as 1/3 octave bands)
A weakness in the upper half of the panel
emerges, disclosing an unexpected periodic
structure.
Question:
is it an effect due to the cradle structure? (*)
6.3kHz
8kHz
10kHz
12.5kHz
As frequency shifts towards higher values,
the narrow horizontal flaw in the upper
board becomes more and more evident
(*) Panel Paintings Initiative of The Getty Foundation
http://www.getty.edu/foundation/initiatives/current/
12.5kHz
Observing the reverse of the panel, the most damaged portion corresponds to a flaw inside the upper board
between the two lines of butterfly inserts
This defect slightly appears in the photograph taken during the ’50s but, on the basis of the present
investigation, it can be assumed that the deterioration process in this area is becoming more significant
Evaluation of the defect size
S oak wood = 0.7g/cm3
S pictorial layer = 0.9g/cm3
f0 = 6.3kHz
f0 = 6.3kHz
d = 3.6mm
d = 3.2mm
6.3kHz
Assuming t = d
i.e. the defect size is the same as the
thickness of the surface layer
mass - air spring system
f0 
1
2
k air
c
 0
M
2
0
 S td
S pictorial layer = 0.9g/cm3
f0 = 6.3kHz
k air  c02 0 S 2 / Vair  c02 0 S / d
M   SVlayer   S St
d = 1.6mm
fundamental resonance frequency
12.5kHz
AIR-COUPLED ULTRASONIC INVESTIGATIONS
(http://www.ultrangroup.com)
11/11/2014
20
AIR-COUPLED ULTRASONIC IMAGING
Maev, Bugaev, “State-of-the art innovative technologies
For non-destructive analysis of the fine art objects”,
Proceedings of the 11 th International Conference ART’14,
Madrid (2014).
Maev, Green Jr. and Siddiolo, “Review of Advanced Acoustical Imaging Techniques for Nondestructive Evaluation of Art
Objects”, Research in Nondestructive Evaluation, Vol.17, No.4, 2006, pp.191-204.
Siddiolo, Maeva and Maev, “Air-coupled imaging method applied to the study and conservation of paintings”, Acoustical
Imaging, Vol.28, 2007, pp.3-12.
Innovative Acoustic Sources: the Parametric Acoustic Array
Exhibition Spaces and Story Tellers
The Parametric Acoustic Array PAA shows a great potential in on site non-destructive
applications thanks to its small size and its high beam directivity
The PAA generates audio frequencies in air by emitting ultrasonic waves modulated in amplitude,
based on the nonlinear propagation of finite-amplitude waves.
The ultrasonic primary beam generates a linear array of virtual sources: the secondary beam with low
(audio) frequency is less attenuated and presents a directivity pattern as narrow as the primary beam
- Gan W. S., Yang J., Kamakura T. (2012), A review of parametric acoustic array in air, Appl. Acoust., 73, pp. 1211-1219.
- Di Marcoberardino L., Calicchia P., De Simone S. (2013), Gli array parametrici: dalla loro scoperta ai giorni nostri, Rivista
Italiana di Acustica, 37 (3-4), pp. 7-17.
- Di Marcoberardino L., Calicchia P., De Simone S. (2014), Gli array parametrici: tra innovazione tecnologica e applicazioni
emergenti, Proceedings of the 41° Convegno Nazionale AIA, Pisa 17-19 june 2014.
DIRECTIVITY PROPERTIES: Beam within – 3 dB
𝟓𝟎
𝟐 𝜽 𝒅𝒆𝒈 ≈
𝑳𝝀
 Small
size
frequency source
low
 Directivity pattern as
narrow as the US
primary beams
Ll linear size in
wavelength
𝟐𝜽𝑾
𝟐 𝝀−
𝒅𝒆𝒈 ≈
𝝅 𝑳𝜶
l- secondary wavelength
La = a-1 absorption distance
a  a1 + a2 - a-
 No side lobes
- 1754 Sorge and Tartini: the most ancient definitions of the
interaction of tones in nonlinear acoustics. Definition of the
generation of a low frequency tone from two high intensity
primary tones (the so called third sound)
- 1957 Westervelt: the first theoretical model, where the
extension of the end-fire array and the distribution of the
virtual sources’ amplitudes contribute to the parametric
generation of sound. The saturation of the primary beams, due
to the extra-attenuation, is evaluated.
- 1963 Westervelt: definition of the Parametric Acoustic Array
(PAA), based on the f1 and f2 interaction, and demonstration
that the existence of the secondary beam, once generated,
results independent from the primary beams.
- 1965 Berktay: extension of the PAA concept; definition of the
self-demodulation of a composite signal - a carrier primary
frequency beam, fc, with low audio frequency amplitude
modulation, fm.
- 1962 Bellin and Beyer:
experimental validation of the
Westervelt’s theory of the end-fire array, in water and in air; the
experiment succeeded in water but failed in air.
- thus during the 70s, the parametric array technology was
implemented for marine applications, such as the
localization and the recovery of buried artworks in the
seabed
- 1974-5 Bennett e Blackstock: while the “controversy over the
very existence of the PAA in Air” was intense, this study presented
the first experimental demonstration of its feasibility. Their study
represented a turning point in the PAA technology and applications.
- 1983 Yoneyama: the first parametric loudspeaker called Audio
Spotlight, able to generate a directive audio beam in selfdemodulation emission.
- during the last two decades the major advancements in
many applicative fields have been done, thanks to the
development of the ultrasonic transducers manufacturing
and pre-processing techniques.
HOLOSONICS®, Audio Spotlight
HAS8
Custom size 8’’
20 cm side
Pompei F.J. (2004), Ultrasonic transducer for
parametric array, US Patent 6,771,785.
Pompei F.J. (2006), Preprocessing method for
nonlinear acoustic system, US Patent 7,062,050.
SOUND PRESSURE LEVEL (SPL)
Measured in an anechoic environment, from 10 cm up to 2 m from the transducer’s surface
BEAM APERTURE: beam width showing points at −6
dB. The beam is included in one major lobe, below 12°
for most of the interesting frequencies.
(Calicchia, Di Marcoberardino, De Simone, Marchal, 2014)
(Calicchia, De Simone, Di Marcoberardino, Marchal, 2012)
PRESSURE FIELD: SPL in the vertical half plane,
crossing the near-field where the end-fire array
determines the formation of the audio beam.
PAA emitting f- = 40 kHz. The presence of
gas beneath the seafloor is evidenced.
Courtesy of KONSBERG.
PAA emitting f- = 10 kHz for sub-bottom study in shallow water.
High directivity in canals allows the reduction of multiple
reflections. Courtesy of INNOMAR.
PAA for NDT of material properties
Selective diffusion of sound in
public and exhibition spaces
TEORIA DUPLEX (RAYLEIGH, 1907)
http://www.ntu.edu.sg/home/ewsgan/
Nanyang Technological University
INTERAURAL
TIME
DIFFERENCE
W. S. Gan, E. L. Tan, and S. M. Kuo, "Audio
projection - directional sound and its
application in immersive communication,"
IEEE Signal Processing Magazine, vol 28, pp.
43-57, January 2011.
INTERAURAL
LEVEL
DIFFERENCE
Binaural reproduction,
3D immersive soundscape
Reconstruction of Historical Soundscapes
Hearing History
Bio-Acoustic Theatres
Conservatorio G. Rossini, Pesaro
http://www.rossinispace.org/
Fragments of Extinction
Biodiversità Acustica delle Foreste Primarie Equatoriali
David Monacchi
http://www.propostesonore.org/MONACCHI_TESTO_ENG.pdf
Cubiculum Musicae:
Experiencing the Renaissance
https://www.youtube.com/watch?v=HtKlbZ-IxK8
Naexus is developed in Dessau (Germany) and Nantes (France). The
device holds a 220° 15m long 1.5m high screen. http://www.naexus.com/
4 projectors create a wide 5:1 image from a single computer !
http://www.odeon.dk/events
SW allowing the reconstruction of the acoustical properties of
specific spaces, and performing auralization thus creating audible
acoustic scenarios
Conclusion
Acoustics crosses many different aspects in the Cultural Heritage
domain, from diagnostics to fruition, from archiving to immersive
environments
Acoustics adds dimensions to the traditional perception and
knowledge of an artwork
Acoustics offers the possibility to capture the intangible aspect of an
environment and an ecosystem perceived as a whole
THANK YOU FOR YOUR ATTENTION!

l`acustica per il patrimonio culturale, tra diagnostica e spazi sonori

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