# Immersive Soundscapes with Networked Vibrating Panels: Bridging Place and Space

Mathieu Barthet, Jérémy Perrouin, Emily Stifter, Vincent Debut, Christine Esclapez

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Mathieu Barthet, Jérémy Perrouin, Emily Stifter, Vincent Debut, Christine Esclapez. Immersive Soundscapes with Networked Vibrating Panels: Bridging Place and Space. 17th International Symposium on CMMR, University College London at UCL EAST, Nov 2025, Londres, United Kingdom. 10.5281/zenodo.17502568. hal-05465825

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# Immersive Soundscapes with Networked Vibrating Panels: Bridging Place and Space

Mathieu Barthet¹[0000-0002-9869-1668], Jérémy Perrouin², Emily Stifter³,
Vincent Debut⁴,⁵[0000-0003-2011-0656], and Christine
Eslapez[0000-0001-5848-9409]¹

¹ Aix-Marseille University CNRS PRISM, Marseille, France
{mathieu.barthet,christine.eslapez}@univ-amu.fr

² Independent artist jeremyperrouin@hotmail.com

³ Aix-Marseille University, Marseille, France emily.b.stifter@gmail.com

⁴ Polytechnic Institute of Castelo Branco, Castelo Branco, Portugal

⁵ NOVA University Lisbon, Lisbon, Portugal

**Abstract.** This paper presents the "Sound, Music and Sciences" (SMS) Lisbon workshop, a research-creation case study aimed at developing student skills in interdisciplinary practice. The project successfully engaged students in collaborative multi-channel soundscape composition, blending theoretical knowledge with practical application. The work culminated in a sound installation presented as part of the NOVA Contemporary Music Meeting (NCMM 2025). The system was developed using frugal technologies (networked Raspberry Pis and a 16-channel vibrating panel system) specifically to democratize access to spatial practice for students. This setup proved to be economical, lightweight, and portable, making multi-channel diffusion accessible and pedagogically effective. Its channel-based spatialization, while simpler than advanced algorithmic techniques, offered effective discrete source placement and immersion with negligible processing latency. The evaluation suggested significant audience engagement, characterized by cognitive intrigue, sensations of travel, and spatial rediscovery of Lisbon. The installation's spatial nature fostered listener movement and social interaction. While the "unusual and hidden Lisbon" theme presented a paradox for local residents, the foreign composers found ample opportunities for exploration. Participants experienced parallel sensations of spatial displacement ("going somewhere") alongside a rediscovery of a city with which they were already familiar. Despite this, the feedback received was overwhelmingly positive, underscoring the approach's potential to foster engagement and inspire future creative projects.

**Keywords:** Acoustic ecology · Soundscape composition · Multi-channel sound installation · Spatial audio · Networked audio · Frugal audio

<figure><img src="image_2.png" /></figure>

All rights remain with the authors under the Creative Commons Attribution
4.0 International License (CC BY 4.0).

Proc. of the 17th Int. Symposium on Computer Music Multidisciplinary Research,
London, United Kingdom, 2025
# 1 Introduction

Sonic arts are evolving towards immersive experiences through advancements in spatial, networked, and distributed audio systems. Acoustic ecology, pioneered by R. Murray Schafer, has reshaped our understanding of the sonic environment as a compositional domain [19]. This practice increasingly uses spatial audio to create auditory illusions of sound originating from specific 3D locations [22]. Immersive sonic environments are now integral to virtual reality and public installations. However, sophisticated spatial audio systems often require significant investment, creating accessibility barriers for artists and institutions. This has led to interest in frugal technology solutions prioritizing simplicity, affordability, and accessibility under resource constraints, which are crucial for democratizing advanced sonic practices [18].

This paper presents the SMS Lisbon workshop, a collaborative initiative from Aix-Marseille University (AMU)'s "Sound, Music and Sciences" (SMS) research training program. The SMS project fosters research and creation skills among students in AMU's interdisciplinary Master's in Acoustics and Musicology and partnering universities. Organized by AMU, Universidade NOVA de Lisboa (UNL), and a sound artist, the SMS Lisbon workshop engaged students in creating soundscape compositions for a multi-channel networked sound installation within specific theme and timeframe constraints. This multi-channel system, by utilizing frugal technologies within a research-creation framework, directly addressed accessibility barriers, thereby establishing the core techno-social novelty of our work through both democratization and skill development. Both the system's development and the installation's reception were evaluated, providing insights into technical implementation, pedagogical effectiveness, and audience engagement. Subsequent sections detail related work, workshop methodology, the networked vibrating panel system, and an evaluation based on interviews and critical analysis.

# 2 Related Work

## 2.1 Acoustics Ecology and Arts: Hearing the World's Sounds

Acoustic ecology, a nascent field emerging in the 1970s, investigates the human relationship with the world through auditory perception. This interdisciplinary field bridges music, sound, musicology, and visual/sound arts, facilitated by their aesthetic and historical permeability since John Cage's pioneering work.

In 1977, R. Murray Schafer, in *The Tuning of the World* [19], conceptualized the environment as an expansive composition of sounds. A soundscape is a combination of sounds forming or appearing within an immersive environment, encompassing natural sounds (e.g., animal vocalizations, wind, rain) and human-generated sounds (e.g., daily occurrences, music, sound design). Acoustic ecology analyzes these soundscapes, whether naturally occurring or resulting from field recording and creative practices.
Interwoven with artistic disciplines, acoustic ecology involves philosophical, aesthetic, phenomenological, acoustic, semiotic, psychological, and psychoacoustic considerations. It is underpinned by an ethic [10] aimed at understanding the world's sonic resonances and their interaction with the human body. Listening to landscapes, natural environments, and urban spaces unveils meanings that illuminate aesthetic, cultural, educational, economic, and social relationships. Recently, it evolved into sound ecosophy ([16]; [8], [3]), representing a civic initiative for environmental transformation and attentive listening to all sonic manifestations [11]. Fundamentally, it is a transdisciplinary field, integrating insights from humanities, exact sciences, and natural sciences.

## 2.2 Soundscape Composition

Soundscape composition creates acoustic works from environmental sounds. Early works applied acoustic ecology principles to document and transform existing sound environments into structured compositions [19]. More recent efforts integrate new technologies, moving beyond fixed media. Contemporary compositions leverage tools like Ambisonics for spatialization [4], networked audio systems for diffusion [24], data sonification [17], and openly licensed audio from databases like Freesound [15]. This blurs the lines between soundscape composition and broader sound installation practices [1]. Technological advancements enable dynamic spatialization and novel presentation formats, expanding acoustic communication principles [22] and pushing audience engagement boundaries.

## 2.3 Frugal Technologies for Spatial and Networked Audio

Frugal technologies prioritize simplicity, affordability, and accessibility. In sonic arts, they are increasingly applied to spatial and networked audio, which distributes sound in space and place to create immersive environments. The high cost of traditional spatial audio installations drives research into frugal methods, especially those leveraging networking capabilities. This includes networked microcontrollers and micro-computers; Chafe and Oshiro [6] demonstrated Jack-Trip's feasibility on Raspberry Pi for cost-effective, low-latency streaming. Michon et al. [14] showcased FPGAs for frugal Wave Field Synthesis (WFS) systems, achieving a 32-speaker setup for under $800, enabling scalable and accessible spatialization over networks.

Web-based frameworks also leverage ubiquitous devices for frugal networked spatial audio. Matuszewski [13] expanded soundworks for distributed multimedia web applications, where audience devices act as networked sound sources. Bevilacqua et al. [5] explored web technologies for collective interaction. Rushton et al. [18] introduced a decentralized client-server system using low-cost microcontrollers for distributed spatial audio, addressing scalability and synchronization via UDP multicast. These efforts lower the barrier to entry for spatial and networked audio, emphasizing accessible hardware and open-source paradigms. Our work focuses on a Raspberry Pi networked system using lightweight vibrating panels for accessible multi-channel diffusion in a pedagogical context. The
novelty of our contribution lies in this techno-social application: providing a re-
producible, low-cost system specifically engineered to facilitate interdisciplinary
student collaboration and democratize access to multi-channel sound creation.

3 SMS Lisbon Workshop: A Research-Creation Approach

3.1 Workshop Theme and Structure

The workshop, a collaboration between AMU, UNL, and sound artist Jérémy Perrouin, involved 18 students from AMU's Master's in Acoustics and Musicology and UNL's Master's in Musical Arts. Spanning six months, it began with organizers defining themes and logistics. The workshop took place from May 2-8, 2025, at UNL, focusing on creating soundscape compositions for public sound installation using networked vibrating panels. This integrated aesthetic and technological goals, aligning with university curricula and a research-creation methodology. Compositions explored themes of an unusual and hidden Lisbon, urban memory, and cultural heritage. The six-day workshop began with introductions and theoretical sessions on acoustic ecology and soundscape composition, followed by hands-on labs covering Raspberry Pi and networked audio, vibrating panel systems, and field recording. Participants formed four interdisciplinary student groups (four or five students from both AMU's humanities/engineering streams and UNL). A day was dedicated to field recording in Lisbon and developing composition ideas. The latter half of the week included a theoretical session on vibrating panel acoustics, group mentoring, intensive group work, finalization of creative and technical aspects, and installation/testing. The workshop concluded with a sound installation at the NCMM 2025 conference held in the outdoor pergola at UNL's Berna campus. An evaluation was conducted through interviews during this installation. Field recordings used Zoom H4 and H5 recorders with windscreens. A Discord server facilitated dissemination of presentations, lab files, and documentation.

## 3.2 Research-Creation Methodology

The workshop and the SMS project employ a research-creation (RC) methodol-
ogy, often interchangeable with practice-based research (PBR). Both define re-
search where creative practice is integral to generating new knowledge, which can
be embodied, tacit, experiential, or quantitative. The creative act functions as an
investigation itself. Giacco and Gosselin [9] define RC as "*a field of research rooted
in academic and institutional contexts within the contemporary art world... a
hybrid methodology fostering constant back-and-forth exchanges between 'artistic
production and theoretical reflection'*." Both RC and PBR emphasize a recip-
rocal relationship where theory and practice mutually inform each other, often
involving a cyclical process of creation, reflection, analysis, refinement, and sub-
sequent creation. Bahng et al. [2] distinguish PBR's aim to generate knowledge
through practice from RC's emphasis on social and community-based engagement. While often solo, RC also develops collaboratively, prioritizing joint execution of projects, as Stévance and Lacasse [21] emphasize. In music, RC "offers a space for dialogue and exchange aimed at bridging knowledge and know-how, respecting the respective requirements of music research and musical practice" [21]. The workshop effectively utilized RC's interdisciplinary nature and collaborative experimental project management, bridging theory and practice with a non-hierarchical convergence of knowledge.

# 4 Design of the Networked Vibrating Panel System

## 4.1 Overall Design Requirements

The acoustic system design was constrained by the workshop timeline, location, and pedagogical context. It needed to be lightweight, economical, and easily transportable across countries. Quick setup in an outdoor public space was essential, and sound diffusion technologies had to be readily learnable by students within a limited timeframe, using open technologies.

## 4.2 Multi-channel Networked Vibrating Panel System

To meet these requirements, we developed a 16-channel audio system based on vibrating panels. These panels were hardwired to Raspberry Pi micro-computers and micro-amplifiers, wirelessly connected to a client computer. PureData served as the audio engine, allowing wireless configuration, portability, and ease of integration. The panel system's design and implementation are detailed next.

<figure><img src="image_3.png" /><figcaption>Fig. 1: Side acoustic panel suspended within the pergola (left) and listeners experiencing soundscapes (right)</figcaption></figure>

**Design and Implementation of the Sound Installation** The sound installation used vibrating acoustic panels, actuated by electrodynamic transducers. The objective was to create an immersive, diffuse auditory experience outdoors
using a discreet, aesthetically mindful solution, while raising student awareness of perceptual considerations in sound spatialization. Figure 1 (left) shows a side acoustic panel suspended within the pergola.

**Panel Material and Acoustic Properties** The acoustic panels were 5 mm thick A1-sized foamboard (carton plume). This material was chosen for its rigidity, which facilitates vibration transmission, and its low weight, which minimizes energy demands on exciters, enabling frugal audio technology. Its inherent inter- nal damping mitigates prominent self-resonances and contributes to a relatively balanced frequency response.

<figure><img src="image_4.png" /><figcaption>Fig. 2: Rear view of the acoustic panel with electrodynamic transducers</figcaption></figure>

<figure><img src="image_5.png" /><figcaption>Fig. 3: Spatial arrangement of the acoustic panels within the pergola</figcaption></figure>

**Transducer Configuration and Sound Diffusion** Each panel was actuated by two electrodynamic transducers (Dayton audio EX25VT2-4, 20W, 4 Ohms) affixed to its rear surface (see Figure 2). Transducer placement was empirically fine-tuned to optimize broad sound diffusion and prevent listeners from local- izing the exact exciter positions. This configuration enhances the perception of an extended, ethereal sound source. The panels exhibit low-directivity sound radiation, fostering sonic envelopment even at close proximity.
**Spatial Arrangement and Installation Logistics** The installation's location within UNL's outdoor pergola (approximately 12m x 5m) facilitated unhindered listener movement. The aim was a 16-channel immersive experience with pervasive sonic presence, accommodating audience mobility while minimizing visual intrusiveness. The panels were spatially arranged to create a three-dimensional immersive field (see Figure 3). Eight panels were suspended vertically around the perimeter, and eight horizontally above the listening area, forming an upper sound layer. This spatial distribution fostered a permeable acoustic bubble where sounds could originate from any direction.

**Suspension System Design and Implementation** The suspension system was engineered for logistical, climatic, mechanical, and aesthetic constraints. Edges were folded 90° (2 cm deep) to create a rigid frame, held by custom 3D-printed brackets with screws and silicone glue. This prevented warping and allowed discreet perforations for slender, tensioned suspension wires. Anchored at elevated points, the wires allowed panels to visually "float," maintaining vibration freedom. The absence of visible structures enhanced the aesthetic impact, intriguing listeners about their operation (see Section 5).

## 4.3 Vibratory Measurements and the Physics of Radiating Panels

Vibrational measurements were conducted to understand panel vibratory motion and acoustical behavior. Characterization focused on the fully coupled system (panel and two exciters as static load). Single admittance measurements were performed by impacting the panel with a hammer and measuring velocity response with a laser vibrometer (Figure 4). Excitations were applied at exciter locations, and vibratory response was measured near a panel corner. As Figure 4 shows, admittance exhibits strong modal character up to 600 Hz, remaining constant at higher frequencies where resonances are less pronounced. The exciter's frequency range, with impedance peaks at approximately 100 Hz and 10 kHz (manufacturer data), delineates the useful frequency range for the exciter-panel coupled system. While limiting low-frequency reproduction, this favors system linearity above 100 Hz, mitigating strong filtering from low-frequency modes.

A notable characteristic, perceivable by rotating the panel 90°, is that panel sound radiation is dominated by dipole behavior. This results from the unbaffled configuration, allowing wave cancellation between both faces, leading to small low-frequency radiation followed by a rapid increase with frequency. Understanding sound radiation from planar structures remains difficult, depending on surface geometry, boundary conditions, baffle presence, surrounding fluid effects, and excitation form [12,23]. Common analysis approaches address (1) modal radiation (sound from a specific mode) and/or (2) overall radiation from point force excitation (many modes contributing). For modal radiation, a plate radiates by its whole surface, edges, or corners, with efficient radiation occurring when acoustic wavelengths are smaller than structural wavelengths. Surface modes are most efficient, followed by edge and corner modes. For point excitation, all three families of modes can be simultaneously excited. Low-order modes can contribute
significantly to radiation even if excitation frequencies are far from their natural frequencies, due to modal damping [7]. Improving radiation efficiency, particularly by coupling modal vibration and radiation models [20] with optimization algorithms, is a clear area for future acoustic panel optimization.

<figure><img src="image_6.png" /><figcaption>Fig. 4: Experimental set-up (left) and measured admittance curves (right).</figcaption></figure>

## 4.4 Networked Audio System Architecture and Implementation

The sound installation used a distributed architecture with 8 Raspberry Pi 5 (Pis) microcomputers, each an independent audio playback unit. Pis were chosen for their compact size, processing capabilities, and audio hardware compatibility. Although Pi 5 specifications exceed basic audio playback needs, they were selected for future workshop scalability and advanced feature integration.

**Hardware Configuration** Each Raspberry Pi 5 had an IQAudio DigiAMP+ via its 40-pin GPIO header. The DigiAMP+ incorporates a Texas Instruments TAS5756M stereo amplifier, providing 2 x 35W output, driving two of the 16 passive acoustic panels. Power was supplied by a KFD 65W 19V 3.42A adapter, connected via panel-mounted barrel connectors for outdoor stability. The DigiAMP+ supplied 5.1V at 2.5A to the Raspberry Pis 5.

For durability, each Pi and DigiAMP+ were housed in a KKSB DigiAMP+ Case. A Pi5 Active Cooler was mounted to each board for optimal operating temperatures, especially during continuous outdoor operation. The array of Pis was secured to the pergola structure with cable ties. Portable batteries were impractical due to high cost and transport restrictions.

**Software Environment** Pis ran Ubuntu with Pure Data (PD) "vanilla" (v0.55-2) for real-time audio. Audio files were stored on 32 GB SD cards. Pis acted as servers, remotely controlled by a MacBook client for starting/stopping audio.
**Network and Remote Management** A dedicated NETGEAR router established the wireless network for the installation. All 8 Raspberry Pi servers and the client MacBook connected to this network for seamless control and data transfer. System configuration and file management on the Pis used GUI tools (VNC Viewer, FileZilla Client) and Terminal commands (e.g., ssh, scp, rsync). iTerm2 and i2cssh (Mac OSX) or ssh (Linux) enhanced efficiency by enabling synchronized command execution across the Pi cluster. The local network enabled very low latency for control operations. Audio transmission between Pis and panels had no latency as they were hardwired. Networked latency and jitter were not issues, as the installation lacked interactive controls.

**Audio System Control and Asset Management** A specific asset management and routing protocol was implemented for multi-channel audio diffusion using Raspberry Pis and PD. MIDI controlled the audio playback system as a sampler: MIDI note values triggered distinct audio recordings on designated output channels, while Control Change (CC) messages managed individual audio file volumes. Each Raspberry Pi operated identically, with all necessary audio and MIDI files replicated. The system had a client ("master") controlling multiple server nodes ("local" Raspberry Pis). A PD program on the client served as the central control unit, managing master gain and triggering MIDI file playback on each networked Raspberry Pi. Individual Raspberry Pis, as server nodes, ran a "local" program for playing audio on specific output channels. These programs dynamically loaded MIDI files based on the Raspberry Pi's hostname and assigned channel, with MIDI notes triggering corresponding audio files. Audio playback was handled by a PD sub-patch, with volume control via MIDI CC messages. Communication between master and local Pis used OSC messages for control commands. Audio processing activated automatically on startup.

To manage asset complexity and ensure sufficient storage, the number of audio files per composition was defaulted to 16. Students produced 16 uncompressed WAV files (16 bits, 44.1 kHz) adhering to naming conventions, and 16 corresponding MIDI files for triggering and volume control. Each group's project folder was copied to every Raspberry Pi. For execution, the main PD patch ran on each Raspberry Pi in non-GUI mode, and the client program on the control computer managed the system. Synchronization among Pis used Ableton Link. Networked communication within PD used OSC messages via `netsend` and `netreceive` objects with UDP for lower latency.

**Spatial Audio Implementation** Each audio file or sound event was directly assigned to a specific acoustic panel, connected to a dedicated output channel. Spatial movement was achieved by manual panning, crossfading between fixed channels, or sequential/concurrent triggering. While 16 panels acted as discrete sound sources, this configuration enabled spatial audio through: (1) **Discrete Source Placement**: 16 distinct points of sound origin allowed listeners to perceive shifts in sound localization based on proximity and orientation to active panels. (2) **Panning/Movement by Amplitude**: Sound movement was gen-
erated by dynamically adjusting amplitude across adjacent panels (e.g., fading out on left, fading in on right for horizontal movement). (3) **Sequential Activation:** Activating panels in sequence created a compelling sense of sound traversing space (e.g., sound "hopping" from panel 1 to 2 to 3). (4) **Layering and Density:** Different sound elements assigned to various panels constructed a spatially rich soundscape, forming a complex sonic tapestry. (5) **Immersion:** Multiple, distributed sound sources cultivated an immersive auditory experience, with more diffusion points contributing to a more enveloping sound field.

# 5 Evaluation

## 5.1 Evaluation Methodology

The artistic intent behind the four soundscape compositions, ranging from 4 to 10 minutes in duration, is detailed in Appendix 6. One composition, mixed for stereo, is publicly available here.

During the public installation, listening sessions were conducted freely from 12:45 pm to 7 pm, inviting passers-by to stand under the pergola. After observing crowd interactions, five individuals who spent significant time in the installation were interviewed with consent. The study aimed to identify the intersection between creative/technical design intentions (especially the 'Unusual Lisbon' theme) and perceived reception, evaluated by listener interpretation and composers' self-assessments. Interviews were audio-recorded, asking about participants' university roles, prior experience with sound installations, and interpretation of compositions. All five participants (3 male, 2 female) were Portuguese and Brazilian students at UNL, recruited outside of our student and staff body, and had limited or no prior sound installation experience. Responses are reported anonymously (e.g., P1, P2). Fields of study included geography, translation, and communications. Figure 1 (right) shows listeners engaging with a soundscape.

## 5.2 Audience Reception and Experiential Observations

Three participants reported profound engagement, describing it as "intrigues your brain and nervous system" (P1) and "relaxing," "immersive" (P4, P5). Three reported a sensation of travel, with one noting "time stops" (P5). These participants consistently described spatial displacement alongside rediscovery of a familiar city. The installation provoked listener movement, confirmed by P4, who wanted to move to hear everything. Figure 1 (right) illustrates groups at various locations, enabling focused listening and social interaction.

Two of the local residents interviewed (P2 and P3) highlighted the paradox of "unusual and hidden Lisbon." As lifelong residents, they recognized most city sounds (e.g., public transit beeps) but struggled to pinpoint exact origins, noting emotional or nostalgic responses. During creative and field recording, most Lisbon residents questioned by students (composers) could not pinpoint "unusual" sounds. A prevalent sentiment was that tourism made Lisbon a shared space,
hindering identification of "hidden" sounds. P2 and P3 suggested discovering the "hidden" Lisbon would require longer integration and access to private moments. Among composers, as foreigners, everything in Lisbon offered exploration. Even small sounds like bus ticket validation beeps instilled a new sense of discovery for P2 and P3.

Time was a prominent factor; all participants interviewed (P2-P5) concurred that the compositions demanded time and patience. Two noted multiple listen- ings were needed for full grasp, while two others recommended an initial listen, then program notes, then additional listens. Listener time constraints challenged sustained engagement. Most UNL students and faculty were unwilling to dedi- cate time to an entire composition, hindering assessment of compositional intent. Limited prior experience and undeveloped critical listening skills may have con- tributed to longer processing time, potentially necessitating repeated exposure. Despite these issues, feedback was overwhelmingly positive. Participants volun- tarily engaged, expressing satisfaction and desire to collaborate or develop their own projects.

5.3 Critical Analysis of the Acoustic Panel Networked System

**Spatialization Approach: Advantages and Limitations** The 16-discrete vibrating panel multi-channel approach offers simplicity and directness in hard- ware implementation and control, making it accessible for pedagogy and rapid deployment. Hardwired audio connections ensure zero latency in direct audio transmission. Its low computational overhead for spatialization, a channel-based approach, ensures negligible processing latency for real-time responsiveness. Re- liance on discrete sound sources and manual amplitude control contributes to its economy and transportability, and it’s readily learnable by students.

However, this approach limits precise and flexible spatialization. Unlike VBAP,
which interpolates virtual sources for smooth movement, this system relies on
manual panning, crossfading, or sequential triggering, resulting in less seam-
less trajectories. It lacks Ambisonics’ ability to encode/decode continuous sound
fields or WFS’s capacity to synthesize consistent spatial perception for multiple
listeners. Thus, while effective for discrete source placement, layering, and im-
mersion, it offers less granular control over continuous virtual source movement
and sophisticated spatial illusions.

Acoustic Panels: Advantages, Constraints, and Artistic Integration

The vibrating panels provide an economical, lightweight, modular, and aesthet-
ically refined solution for sound diffusion. They promote re-evaluation of tradi-
tional sound reinforcement and exploration of auditory perception in immersive
contexts. This blurs distinctions among sound source, physical space, and acous-
tic image, as noted in the evaluation (Section 5.2). The spatial layout extended
artistic intent, encouraging physical exploration. Timbre, spectrum, and inten-
sity variations became integral to the holistic auditory experience.
During setup, some issues could not be fully resolved within the timeframe,
preventing iterative adjustments between composition, spatial design, and sys-
tem calibration. Compromises were necessary. A significant challenge was the
lightweight panels' sensitivity to wind, which necessitated setting the side verti-
cal panels at a higher position (see Figure 1 on the right). A rigid aluminum frame
was considered impractical for transport. Insufficient pergola height prevented
optimal horizontal panel placement for uniform coverage, leading to localized
overhead sounds and uncovered zones. More suitable positioning or doubling lat-
eral sources might have addressed this. Despite advantages, panels inefficiently
reproduce frequencies below 150 Hz beyond one meter. This constraint was em-
braced: students adapted compositions to system qualities, leveraging perceptual
variability from movement. The setup functioned as both a diffusion system and
a creative constraint, fostering experimental spatial composition.

6 Conclusion

This paper presented the SMS Lisbon workshop, a research-creation case study
developing a frugal, networked vibrating panel system for immersive sound-
scapes. The initiative successfully engaged students in collaborative multi-channel
soundscape composition, bridging theory and practice. By utilizing a frugal sys-
tem based on Raspberry Pis and hardwired acoustic panels, we demonstrated a
novel model for pedagogical, interdisciplinary research-creation that is econom-
ical, lightweight, and portable. Its channel-based spatialization offered effective
discrete source placement and immersion with negligible processing latency. The
evaluation suggested profound audience engagement among the interviewees,
characterized by cognitive intrigue, sensations of travel, and spatial rediscovery
of Lisbon. The installation's spatial nature fostered listener movement and social
interaction. While the "unusual and hidden Lisbon" theme presented a para-
dox for residents, composers found new exploration opportunities. Listener time
constraints, however, highlighted challenges in assessing specific compositional
intent. Despite these issues, the overwhelmingly positive feedback from the inter-
viewees underscored the approach's potential to foster engagement and inspire
future creative projects. Future work will enhance the system's environmental
robustness and explore more flexible spatialization methods while retaining its
frugal nature. Enhancing acoustic panel radiation efficiency while preserving
their lightweight and portable nature is a clear avenue for future optimization.
Further research will investigate the long-term impact of such pedagogical ap-
proaches on interdisciplinary skills and artistic practice.

**Acknowledgments.** We extend our warm thanks to Antoine Gonot and Isabel Pires for their invaluable contributions to the workshop. This work received support from the French government under the France 2030 investment plan, as part of the Initiative d'Excellence d'Aix-Marseille Université – A*MIDEX<fnref n="6" /> - AMX-22-IN2-91.

<footnote n="6">⁶ https://www.univ-amu.fr/en/public/amidex-foundation</footnote>
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# A Artistic Intent of Soundscape Compositions

This appendix section presents the artistic statements from the students for the four soundscape compositions.

**Safe Flight Back (9')** by Antoine Bordus, Maël Lelievre, Léna Peltier, and Emily Stifter This piece uses field recordings to capture Lisbon's essence while exploring the "unusual." As foreign students, what we found unusual were constant airplane takeoffs/landings and different languages. We embraced the idea of "things in the air": planes, birds, falling water droplets, and the voice. "Safe Flight Back" journeys from anthropophony (machines) to human bio-phony (voice/music), to geophony and natural biophony (animals/water). Main field recording places: Alfama, Santa Clara, Graça garden, Calouste Gulbenkian Foundation Garden.

**Passagens decompostos (6'56)** by Ombeline Boucher, Iwan Paturel, Nathan Moreau, Johan Moulard, and Emilie Makaymous Passagens decompostos is a Lisbon listening experience through sonic deformation and transformation. A crescendo guides the piece from familiar sounds to distorted, abstract worlds. Sound spatialization creates auditory immersion in a constantly mutating space, where sensory overload leads to desensitization, as per Georg Simmel. The piece conveys emotional detachment from urban stimuli, using an-thropophonic recordings from Lisbon's docks. This soundscape expresses urban experience, reactivating often unconsciously anesthetized listening. Main field recording places: MAAT, Doca de Alcantara, R. Sao Sebastiao da Pedreira.

**BerrystoPY1 (10')** by Giovanni Preato, Lorenzo Pernice, Ivan Bern-abdellah, Anthony Silva Pinto In a world where chaos reigns alongside order, humans embody the dystopia of an earth in distress. This Lisbon sound-scape traverses the cycle of human societies in perpetual reconstruction. In a context of hypertension, listeners reflect on their position within an ecological crisis. Structured in three parts ("nature, transition, human"), our dark ambient piece mixes concrete sounds evolving into electronic sounds. We used techniques of molding and entangling plane sounds to dialogue the world with the human. Main field recording places: Botanic garden, around Belem monastery.

**Esquecer (4')** by Julia Araujo, Jawad Rezgui, Zoé Rebeyrat, and Max-ence Seguin Tough day... Lisbon presses and jostles me, people look without seeing. I arrive at Terreiro do Paço pier, assaulted by the ferry's mechanical rhythm. We crowd on the pontoon, oil smell filling nostrils and hearts. Eager to cross the Tagus, to bury myself in charm, calm, and sand. Even for a moment before plunging back into the city of Seven Hills. The piece has a cyclical, three-part form. The first part features an intense rhythm, evoking the metallic sounds of the city. As the protagonist reaches the port to embark, the second part offers a calming transition, immersing them in the sounds of nature. The third part marks a return to the city, mirroring the rhythmic intensity of the initial section. Main field recording places: Barreiro, ferry boat.