1Writing about the work of someone who has been a supervisor, a colleague and a friend is never simple. Instead of attempting an overview of his whole scientific and academic work – well beyond the scope of this paper – we propose to revisit several moments in which sound shaped Grégoire Chelkoff’s conceptual and methodological developments. This text should be understood as a navigation through his ideas, gradually leading us to the notions of forms, formants and formalities, which he first developed during his PhD research (Chelkoff, 1996) and later presented in an article translated into English here. While the works discussed here gravitate around the emergence of these concepts, they belong to a wider set of scientific and pedagogical inquiries that we do not claim to retrace in full. Our aim is simply to put selected elements into perspective, offering a humble introduction and contextualisation to this publication.
- 1 This quotation, like all those that follow, has been translated by the author.
2Grégoire Chelkoff was an architect, a researcher and a lecturer at the Grenoble School of Architecture, and he contributed to the creation of a research group in 1979 that became later the CRESSON laboratory. He first engaged with research on sound as a student working with Jean-François Augoyard, co-founder of CRESSON (Augoyard et al., 1982), before pursuing this line of inquiry as a researcher on his own. From his earliest work, he examined public space through the lens of sound, seeking to understand what he called its “sound forms”1 (Chelkoff, 1988). His intuition was then that a shared environment is shaped not only by the sounds that circulate within it, but also by the act of listening to it. That meant listening to others as well as listening to one’s own presence.
3It is through this “collective sound dimension”(Chelkoff, 1988), understood as a fundamental feature of public space, that questions of spatiality, sonic specificity and spatial limits first emerge in his work. He then pointed to the need to consider simultaneously the sound environment – which contributes to the specific qualities of a place – and the interactions between space and social practices. Beyond spatial morphologies or programmatic functions, he argued, sound phenomena reveal a form of social consistency. In this sense, sound – beyond the usual framing as noise or nuisance – offers a means of approaching the uses and practices of public spaces.
- 2 Among the various effects, we can cite the elementary effect of coupure (cut), which was coordinate (...)
4It is also in this period that the “sound effects” took shape. Within the CRESSON research group, these effects were collectively defined through a shared effort to describe recurrent sonic phenomena encountered in everyday environments. Grégoire Chelkoff played an active role in this multidisciplinary work, particularly through his work on public spaces.2 The Répertoire des effets sonores (Sonic Experience: A Guide to Everyday Sounds), consolidated in its 1995 edition (Augoyard & Torgue, 1995), emerged from this collective process and provided a first set of analytical tools to describe how specific sonic phenomena structure perception and attention in everyday situations. More fundamentally, work on sound effects brought forth a key question: how sound operates and then how it is perceived within situated contexts, especially at the architectural scale. Sound propagates through material and spatial conditions, is produced by uses and practices, and is perceived through individual and collective interpretive frameworks. An effect therefore captures the interplay between physical propagation, social activity and the perceptual frameworks through which it is received.
5Across multiple studies, Grégoire Chelkoff’s work brings forth several objects of investigation and lines of reflection about how sensory experience informs architectural and urban design. In this perspective, research on sound effects plays an essential role. Beyond providing tools for describing and assessing situations, these studies opened up some of the first reflections on architectural and urban design processes. In the following years, the notion of sound effects would be explicitly mobilised as a support for design (Odion et al., 1996) and would then mark a first step toward a broader question: how can ambiances not only be analysed, but also become part of the architectural and urban project?
- 3 For a general introduction to this concept, see “L’environnement sensible et les ambiances architec (...)
6In the French context, and particularly within the CRESSON laboratory, the notion of ambiance designates the way spaces are lived, perceived and shared through the interplay of identifiable physical phenomena (light, temperature, sounds, etc.), the situated perception of the body in motion, and the psychosocial representations that permeate them. Perceiving bodies, which are both receivers and producers, are at the heart of this dynamic. Ambiance is thus formed at the intersection of material signals, individual perceptions and collective frameworks of meaning.3 Ambiance is then approached as a situated and relational process, and it is within this perspective that sound became, for Grégoire Chelkoff, a privileged entry point: not as an isolated sensory domain, but as a means to grasp how environments form through experience.
7This gradual move from analysing sonic situations to considering how they might inform the shaping of spatial dispositions marks a turning point. It is precisely this projected, or “to-be-projected” dimension of ambiances that Gregoire Chelkoff would continue to work on, by focusing his reflections on architectural devices and, more broadly, on spatial design. On this same question, the notion of formant (developed later in this text) gradually takes on a more “embodied” form in the project. A discussion between Grégoire Chelkoff, Jean-Paul Thibaud, Pascal Amphoux and Jean-François Augoyard explores Gregoire’s ‘formants’ hypothesis. (These debates are the result of an internal seminar held by the CRESSON team in 2001. They were then transcribed, edited and rewritten for publication in the book “Ambiances en débats” alongside 12 articles written by CRESSON authors) (Amphoux et al., 2004). A concluding exchange, in which the formant is questioned as a descriptor and/or generator of sensitive experience, is particularly striking:
“Pascal Amphoux: And is the issue rather to describe something or to generate form?
Grégoire Chelkoff: For me, it’s the same thing. […] There is also a dimension of becoming in design, an imagined becoming. This is where it connects with the problem of ambiance, because from the point of view of architecture as said, drawn or thought, I think there are formants that underpin different coherences of ambiance, depending on the interactions imagined with the environment. […] I tell myself that, in order to design with ambiance in mind, we need to bring into play the formant registers that are likely to actualise forms. And perhaps some of them are more important, or particularly compelling, at a given moment… But then we need to be aware of this when we question the ambiance capacity of an architectural disposition.”
8The notion of formant emerges precisely where the notion of effect reaches its limits. While effect helps describe how certain sonic phenomena emerge and/or are made noticeable, they do not always account for the processes through which a sensory or affective state is formed. Except for a few particular categories, the articulation between phenomena that can be sensed and their associated perceptions remains insufficiently addressed. The concept of formant then tries to address this gap relating to the dynamic interplay that is never fixed and that contributes to shaping an ambiance.
- 4 Although this work focuses on the sonic dimension, by studying situations in which it is dominant, (...)
9From this moment onwards, a specific attention to the articulations between “sensory elements”, and more broadly to sensory articulations, becomes central in Chelkoff’s work. The research project that most clearly outlines this perspective in relation to sound is undoubtedly Prototypes sonores architecturaux (Architectural sound prototypes). The aim of this research was both to establish a catalogue of sonic configurations associated with built situations and, following this classification, to construct spatial and sonic prototypes that put these categories to the test as project tools. Three sonic “configurations” then arise from this work: articulation, limit and inclusion (Chelkoff, 2003). While not aiming to be exhaustive, these three configurations shared a common approach: they all simultaneously interrogate spatial typologies, everyday uses and forms of sensory perception.4
10The limit configuration illustrates the sonic shift from one situation to another. It brings into play characteristics of form that orient the separation between spaces (walls, bridges, porticos, parapets, openings, etc.), but also sensory situations that may constitute a limit (for example, a sonic mass in open space, or a competition between sources that creates a state of transition). Such a sonic situation then offers affordances for practices at the limit or “on the limit” (settling at the edge or at the threshold of this sonic shift): “The notion of limit opens up choices for the listener and concerns […] the possible grip on the situation through the choice of a position from which to establish a particular relationship of listening [or interaction] with the context.” (Chelkoff, 2003).
11The articulation configuration focuses on sonic transformations in time and space as a function of movement. These situations interrogate sensitive transitions by focusing in particular on spatial devices such as thresholds, passages and intermediate spaces, as well as more singular configurations such as angled spaces, funnels or chicanes. The sonic dimension of these sensory transitions is manifested, for example, through effects of cut or fade, offering opportunities for use through the transformation of sound as it passes through the device, but also through the way in which this transformation is experienced. Here, it is primarily the act of passing from one space to another that takes place in and through use, essentially through bodily movement.
12The third configuration, inclusion, describes situations of sonic nesting that result from arrangements of different layers. This category refers to spaces which, through their morphologies and/or their materialities, render perceptible the relationship between these “nested” sonic layers (staircases, inner courtyards, alcoves, interior courtyards or block interiors), but also configurations of extraction that can reframe these different planes (for example, elevated spaces or open field). These inclusion spaces are often associated with waiting or dwelling, depending less on the movement of the listener than on their sonic practices (contemplation, waiting, verbal interactions, specific sonic activities, etc.). Their distinctive feature is that they create a feeling of being included in something, without it being possible to perceive this inclusion from “outside” (i.e. the sensory environment that contains).
13In this research on architectural sound prototypes, a proposal for analysing architectural and urban situations at three levels also emerges: morphological and physical dimensions; perceived phenomena; and, finally, practices and representations associated with these two levels. These correspond, in a sense, to forms and formants, in interaction with what Grégoire Chelkoff also describes as relations between the “constructed device, circumstances of public use and ambient flows”(Chelkoff, 2003). Here we can clearly see that the three categories – forms, formants and formalities – are conceived in their interdependence rather than as separate registers and the proposal is then to understand their recursive interrelation.
14Forms designate the material and spatial configurations that condition the emergence of sensory situations. Formants refer to the operative articulations that render these configurations effective – those convergences of morphology, materiality, propagation, posture, circulation or activity that ‘give form’ to an ambiance. Formalities, in turn, describe the patterned ways in which situations are inhabited, appropriated, interpreted or regulated, completing the loop between spatial dispositifs and lived practices. Rather than being a classificatory system, it operates as a dynamic tool through which urban situations can be understood in their unfolding and mutual shaping.
15Seen in this light, the formant makes it possible to conceptualise the passage from form to experience: it names the dynamic process through which spatial configurations become affective or operative situations. It is therefore not an additional layer but a mediating dimension, revealing how actions, perceptions and environmental conditions interact to “form the form”. Far from a static taxonomy, the triad forms–formants–formalities constitutes a relational framework for analysing how urban ambiances emerge, stabilise and transform.
16This conceptual shift was followed by a growing attention to the experiential and experimental dimensions of designing through ambiances. The Prototypes sonores architecturaux (architectural sound prototypes) research marks an important turning point in this regard: it opened a broader reflection on prototypes, experience and experimentation – three notions that became central in Chelkoff’s subsequent work. Rather than treating prototypes merely as technical demonstrators, these studies approached them as situated devices through which ambiances could be tested, transformed and understood.
17By testing specific sonic configurations (Chelkoff, 2003) or, more broadly, sensory configurations (Liveneau & Chelkoff, 2008), these experimentations foregrounded the value of constructed devices tested through the “use in movement” (Chelkoff, 2005). They also revealed how experimentation creates a form of reciprocity between design methods, scales of intervention, durations of inquiry and modes of evaluation: each experimental setting reshapes the methodological approach, just as the method reshapes the experiment.
18As Chelkoff later wrote in Expérimenter l’ambiance par l’architecture (Experiencing ambiance through architecture):
“The task is to conceive a working process that feeds ways of doing design […] based on hypotheses relating to ambiances, and to define horizons of production linked to dwelling practices […] and the sensory engagements they involve.” (Chelkoff, 2018).
19Beyond work aimed at the acoustic efficiency (or more broadly any “sensory efficient” constructed device), these reflections on experimentation and experience make it clear that the architectural discipline – with everything it implies in terms of relations, uses, space, materialities and sensitivities – remains for Grégoire Chelkoff at the centre of his research practice. Ambiance is positioned both as a driver for design and as an object of research in its own right, beyond the mere question of reception.
20With that in mind, a common thread emerging from those works is the centrality of the moving and perceiving body (the body in action) as both a starting point of reflection and a methodological attunement. Experiences offer, in this sense, a pretext, an exploratory tool and a concrete method for investigating how situations unfold at specific spatial and temporal scales. By engaging the body through situated experiments, it becomes possible to anchor analysis in the rhythms, thresholds and transitions of experience. Through “sequences of actions,” one can, as Grégoire Chelkoff notes, “define a spatial scale and a temporality of the experience and of the place” (Chelkoff, 2003). This approach shows that the very parameters through which we analyse or design a situation – its scale, its duration, its transitions – could be actively produced and thought through bodily engagement. This is why experiential investigation became essential here when questioning ambiances and their design, so that the conditions of experience inform and resonate with the intentions of projection.
21We see in the work of Grégoire Chelkoff a continuous effort to think and experiment with methods for understanding sensory situations, addressing both why and how they occur. This leads to and starts from, among other things, the proposal of forms, formants and formalities, which still play today an important role when the task is to question architecture, uses and ambiances in research. It is especially relevant as a tool of systematic categorisation that tends to include qualitative aspects of the ambiances, allowing us to place them in parallel with more quantitative indicators (measurements or indices, for example). Indeed, these questions continue to resonate today in various contemporary inquiries – whether dealing with sonic interrelations, environmental sensibilities, or shifting articulations between built forms and lived practices – attesting to the lasting relevance of the conceptual tools he developed.
22This continuity is also evident in the methodological orientations that emerged from his work: the mobilisation of the perceiving body, the systematic anchoring of investigations in spatial and temporal situations, and the continual remodelling of methods to suit each context. Such orientations continue to shape the research group’s practices today.
23One of the most notable resources of this kind is Cartophonies,5 whose current role as a shared platform stems directly from this long-standing attention to situated sonic environments. In this sense, Cartophonies should not be understood as a separate tool developed alongside these reflections, but as a methodological extension of them: a way of operationalising the relations between forms, formants and formalities through situated listening practices and shared representations of sonic environments.
24The proposal emerged from a research project, named Cartophonies (Chelkoff & Laroche, 2015), to develop a sound mapping tool. Based on the sonic and spatial characteristics of places, as well as on the practices associated with them, the initial aim was to produce a cartography of the ordinary sonic ambiances of a town and its near territory. This work was then progressively extended to other research projects and to CRESSON’s broader sound collections, with a clear intention to organise, archive and make available for sharing the knowledge produced around sonic environments. Today, this effort takes the form of a website called Cartophonies.fr, and it has become a huge corpus of sonic environments analysed through their built forms, social practices and acoustic characteristics. This resource now plays an important role in assembling and cross-referencing materials from all around the world and across many research projects from the CRESSON laboratory relating to the lived experience of spaces and ambiances.
25Some other works could of course have been discussed here: studies on natural light, inquiries about posture and affordances in urban situations, research on architectural dispositifs or on multiple characteristics of public spaces among many others. Taken together, these contributions form a coherent trajectory in which each proposition is, in a way, linked to another. But the triad of forms, formants and formalities is, a posteriori, a compelling thread linking this diverse body of work – not as a final synthesis, but as a conceptual framework that allows spatial configurations, sensory phenomena and situated practices to be approached in their interdependence. While our intention here has been to offer a concise introduction to these developments, this text also stands, in its own way, as a modest tribute to the clarity, openness and generosity with which Grégoire Chelkoff approached research, and to the intellectual and personal companionship that shaped so many of my understandings.
26The translated article that follows introduces these notions of Forms, Formants and Formalities in their original formulation and offers a synthetic entry into Grégoire Chelkoff’s theoretical and methodological contribution to the field of ambiances. This introduction was therefore not meant as a retrospective, but as an invitation to read that text with an appreciation of the long and patient trajectory from which it emerged and which continues to inform methodological and conceptual reflections today.