Sylvain Haupert

Muséum National d'Histoire Naturelle · Origines et Évolution

Political responses to the COVID-19 pandemic led to changes in city soundscapes around the globe.From March to October 2020, a consortium of 261 contributors from 35 countries brought togetherby the Silent Cities project built a unique soundscape recordings collection to report on local acousticchanges in urban areas. We present this collection her...

The concept of a soundscape is found in both ecology and music studies. Nature soundscapes and soundscape compositions are analyzed by both disciplines, respectively, to understand their biological diversity and ecosystem functioning and to interpret their compositional structure. A major challenge for both disciplines is visualizing the informatio...

Open audio databases such as Xeno-Canto are widely used to build datasets to explore bird song repertoire or to train models for automatic bird sound classification by deep learning algorithms. However, such databases suffer from the fact that bird sounds are weakly labelled: a species name is attributed to each audio recording without timestamps t...

1. Passive acoustic monitoring of biodiversity is growing fast, as it offers an alternative to traditional aural point count surveys, with the possibility to deploy long-term acoustic surveys in large and complex natural environments. However, there is still a clear need to evaluate how the frequency-and distancedependent attenuation of sound as we...

Passive acoustic monitoring of biodiversity is growing fast, as it offers an alternative to traditional aural point count surveys, with the possibility to deploy long‐term acoustic surveys in large and complex natural environments. However, there is still a clear need to evaluate how the frequency‐ and distance‐dependent attenuation of sound as wel...

The concept of soundscape was originally coined to study the relationship between humans and their sonic environment. Since then, several definitions of soundscapes have been proposed based on musical, acoustical and ecological perspectives. However, the causal mechanisms that underlie soundscapes have often been overlooked. As a consequence, the t...

The collection and interpretation of field data is a prerequisite for informed conservation in protected environments. Although several techniques, including camera trapping and passive acoustic monitoring, have been developed to estimate the presence of animal species, very few attempts have been made to monitor ecological functions. Pollination b...

Context One mainstay of soundscape ecology is to understand acoustic pattern changes, in particular the relative balance between biophony (biotic sounds), geophony (abiotic sounds), and anthropophony (human-related sounds). However, little research has been pursued to automatically track these three components. Objectives Here, we introduce a 15-y...

Nondestructive evaluation of closed cracks is one of the most challenging problems in ultrasonic testing. Here, we propose a novel closed-crack imaging technique combining ultrafast phased-array with pump excitation. The pump excitation with kHz frequency can effectively induce the crack opening/closing behaviors since it can generate a large displ...

Passive acoustic monitoring is increasingly being applied to terrestrial, marine and freshwater environments, providing cost‐efficient methods for surveying biodiversity. However, processing the avalanche of audio recordings remains challenging, and represents nowadays a major bottleneck that slows down its application in research and conservation....

Although the understanding of the nonlinear ultrasonic scattering at closed cracks is essential for the practical application of nonlinear ultrasonic phased array, it has yet to be elucidated because of the lack of experimental techniques. This study proposes fixed-voltage fundamental wave amplitude difference (FAD) with radarlike display. We first...

A participatory monitoring programme of an exceptional modification of urban soundscapes during Covid-19 containment.

Tropical forests are facing threats that may affect the dynamics of seed dispersers which participate in the forest regeneration. To implement appropriate conservation programs, it appears necessary to monitor seed dispersers and to estimate their response to local changes. Here, we used non-invasive ecoacoustic methods to monitor the activity of a...

The nondestructive evaluation of closed cracks is a challenging subject in ultrasonic testing. Recently, nonlinear ultrasonic phased array with fixed-voltage fundamental wave amplitude difference (fixed-voltage FAD) has been proposed as a practical approach. In this study, the maximum incident wave amplitude, which is one of the most critical param...

An ultrasonic technique for imaging nonlinear scatterers, such as partially-closed cracks, buried in a medium has been recently proposed. The method called fundamental wave amplitude difference (FAD) consists of a sequence of acquisitions with different subsets of elements for each line of the image. An image revealing nonlinear scatterers in the m...

Pioneering measurements of elastic nonlinearity were static methods leading to the thermodynamic diagram that shows the relations between pressure, volume, and temperature (p-v-T diagram) [1]. The dependence of the bulk elastic modulus on the pressure, i.e., a measure of nonlinear elasticity, was deduced from this diagram. In the beginning of the t...

Ecoacoustic research mainly relies on signal and data analysis. Beyond manual inspection, the current solutions to decipher the content of population, community or soundscape recordings either refer to supervised classification methods that need labelled data (e.g. SVM, CNN, RF) or to global diversity indices that totally avoid species identificati...

Crack closure is one of the serious issues in ultrasonic testing that may cause underestimation or misdetection. Nonlinear ultrasonics is a primary means to solve this problem. Recently, several techniques using ultrasonic phased arrays to measure elastic nonlinearity, referred to commonly as nonlinear ultrasonic phased array imaging, have been pro...

Retrieving bone micro-architectural parameters non-invasively using ultrasound would enable the monitoring of bone loss, and the follow up of the efficacy of treatments. When ultrasound propagate in bone in the MHz range, multiple scattering is non-negligible, and we demonstrate that it is possible to take advantage of it. We propose methods based...

Measurement of the dependence of the elastic moduli on the strain, i.e., the characterization of nonlinear elastic properties of solid media, poses intrinsic experimental difficulties. The Dynamic AcoustoElastic Technique has been recently developed as an efficient tool for the determination of the modulus in both compression and tension. The goal...

Dynamic acousto-elasticity (DAE) provides a unique way to observe nonlinear elastic features over an entire dynamic stress cycle including hysteresis and memory effects, detailing the full nonlinear behavior under tension and compression. This supplemental information cannot be observed with conventional nonlinear ultrasonic methods such as wave fr...

The dynamic acousto-elasticity (DAE) technique uniquely provides the elastic (speed of sound and attenuation) behavior over a dynamic strain cycle. This technique has been applied successfully to highly nonlinear materials such as rock samples, where nonlinear elastic sources are present throughout the material. DAE has shown different nonlinear el...

The objective of the study was to evaluate the ability of a nonlinear ultrasound technique, the so-called nonlinear resonant ultrasound spectroscopy (NRUS) technique, for detecting early microdamage accumulation in cortical bone induced by four-point bending fatigue. Small parallelepiped beam-shaped human cortical bone specimens were subjected to c...

Anisotropy of wave velocity and attenuation induced by a dynamic uniaxial strain is investigated by dynamic acoustoelastic testing in limestone. Nonlinear resonance spectroscopy is performed simultaneously for comparison. A compressional resonance of the sample at 6.8 kHz is excited to produce a dynamic strain with an amplitude varied from 10(-7) t...

While cell analysis is conventionally performed on 2D slices, novel micro and nano-CT system opens new perspectives in this area. Here, we show that synchrotron radiation (SR) micro-CT is well suited to analyze the 3D distribution of osteocyte lacunae in bone tissue. Osteocytes are receiving increasing interest in the comprehension of bone diseases...

The long-term perspective of this study is to implement in vivo some new noninvasive methods to monitor the bone prostheses sealing or osseointegration (dental implants, hip prostheses). Although the most widely used clinically, X-ray radiography suffers from low sensitivity, limiting for instance its ability to detect early loosening of a prosthes...

Recently the concept of probing nonlinear elasticity at an interface prosthesis/bone has been proposed as a promising method to monitor the osseointegration/sealing of a prosthesis. However, the most suitable method to achieve this goal is a point of debate. To this purpose, two approaches termed the scaling subtraction method and the cross-correla...

Accumulation of bone microdamage is suspected to lead to severe impairment of mechanical properties with an increase in skeletal fragility and fracture risk. The objective of the study was to evaluate the sensitivity of nonlinear resonant ultra-sound spectroscopy (NRUS) measurements to the propagation in cortical bone of a single microcrack induced...

A large number of models have been proposed in the field of nonlinear elastic wave propagation in damaged solids to validate experimental observations with theoretical predictions. In this contribution, we distinguish between "distributed" and "interface" implementations of nonlinearity, and deduce particular properties for the differing models. Fo...

Bone microdamage characterization as well as its involvement in bone metabolism or bone fragility remains a challenge, especially because no existing techniques are well suited to its measurement. Non invasive techniques for detecting and monitoring bone microcracks accumulation and propagation are thus highly desirable. The objective of this thesi...

The objective of the study was to evaluate the sensitivity of nonlinear resonant ultrasound spectroscopy (NRUS) measurements to the accumulation of damage in cortical bone by fatigue or by controlled crack propagation. Two groups of human cortical bone specimens were prepared from the femoral mid-diaphysis. The specimens from the first group were t...

This study broadens vibration-like techniques developed for osseointegration monitoring to the nonlinear field. The time reversed elastic nonlinearity diagnostic is applied to two mock models. The first one consists of tightening a dental implant at different torques in a mock cortical bone; the second one allows one to follow glue curing at the in...

The aim is to assess the nonclassical component of material nonlinearity in several classes of materials with weak, intermediate, and high nonlinear properties. In this contribution, an optimized nonlinear resonant ultrasound spectroscopy (NRUS) measuring and data processing protocol applied to small samples is described. The protocol is used to ov...

Accumulation of bone micro-damage is suspected to lead to severe impairment of mechanical properties with an increase in skeletal fragility and fracture risk. The objective of the study was to evaluate the potential of Nonlinear Resonant Ultrasound Spectroscopy (NRUS) for measuring micro-damage accumulation in cortical bone using four-point bending...

Resonant Ultrasound Spectroscopy (RUS) is the gold standard method for anisotropic elasticity assessment of millimeter-size samples. However, the usual implementation of RUS fails to measure bone because of its high mechanical damp-ing, which prevents the resonance frequencies measurement. The aim of this study is to demonstrate that RUS method can...

In this study, we propose an optimized NRUS measuring and data processing protocol dedicated to small bone samples specially designed to be used in a four-point bending mechanical fatigue test. Our goal was to assess the elastic and dissipative hysteretic nonlinear parameters repeatability with the proposed protocol using several classes of materia...

We evaluate the sensitivity of multimodal nonlinear resonance spectroscopy to torque changes in a threaded interface. Our system is comprised of a bolt progressively tightened in an aluminum plate. Different modes of the system are studied in the range 1–25 kHz, which correspond primarily to bending modes of the plate. Nonlinear parameters expressi...

Il a été montré que les pics de pression large bande détectés après insonification (post-excitation) de microbulles isolées sont liés à la destruction et la cavitation inertielle de ces microbulles. Cette étude a permis d'analyser la réponse post-excitation de microbulles de l'agent expérimental BR14 (Bracco Research SA -Genève) ainsi que de Defini...

We evaluate the sensitivity of multimodal nonlinear resonance spectroscopy to torque changes in a threaded interface. Our system is comprised of a bolt progressively tightened in an aluminum plate. Different modes of the system are studied in the range 1–25 kHz, which correspond primarily to bending modes of the plate. Nonlinear parameters expressi...

Passive cavitation detection was used to improve the experimental characterization of single ultrasound contrast agent microbubble responses to short, large amplitude pulses. Two situations were examined: isolated microbubbles in an unconstrained environment, and isolated microbubbles flowing through a tube. The microbubbles were categorized accord...

Cortical bone is a compact tissue with anisotropic macroscopic mechanical properties determined by a microstructure and the quality of a mineralised collagen matrix. Anisotropic elastic properties and strength are usually measured on different groups of sample which can hardly be pooled; as a consequence little is known on the relationships between...

The current work aimed at comparing, on site-matched cortical bone tissue, the micron-level elastic modulus E(a) derived from 200 MHz-scanning acoustic microscopy (SAM) acoustic impedance (Z) combined with bone mineral density (assessed by synchrotron radiation microcomputed tomography, SR-mu CT) to nanoindentation modulus E(n). A good correlation...

Nanoindentation allows measurements of local mechanical properties of bone tissue. Scanning acoustic microscopy (SAM) provides images related to bone density and elasticity. In both techniques, the estimation of Young modulus (E) relies on the accuracy of Poisson's ratio value (sigma). In cortical bone, sigma varies between 0.15 and 0.45 but, is cl...

Real-time quantitative ultrasound imaging (QUI) produces images of bone properties with the advantages of being non-ionizing, portable and repeatable. A real-time QUI technique has been proposed, based on two 2-D arrays (24x24 transducer elements) to produce a confocal spherical focusing in transmit and receive modes. However, the electronics to ma...

The invention relates to the field of digital subtraction angiography. An image processing method is applied to a digitized mask (100) and to a sequence of digitized opacified images (101). A logarithmic function (105) is applied to the values of the pixels of the digitized mask and to the values of the pixels of the sequence of digitized opacified...

An experiment was conducted in a virtual town to investigate episodic memory and false memory assuming that an active condition would increase memory compared to a passive condition. Subjects were university undergraduate students; active participants drove a car through the city, and passive participants were only passengers. Subjects were instruc...

in an evolving interface. Our system is comprised of a bolt progressively tightened in an aluminium plate. This apparently simple system is surprisingly complex. Dierent modes of the system, identied using Finite Element Modelling, are studied in the range 1-25 kHz. These modes mostly correspond to bending modes of the plate. For each mode, nonline...

L'objectif de ce travail est de présenter une méthode qui permet, sur un même échantillon osseux, la mesure de propriétés élastiques anisotropes et de la résistance à la fracture. Le module de Young et la contrainte maximale à la rupture sont obtenues par un test de flexion trois points. Deux méthodes ultrasonores originales adaptées à la forme des...