Thinking about sound through some recent works of sound art is the project of this series of chronicles. The artists do not only make of it a material that they expose and work, they reflect it and question it, making sensitive what, in our daily experiences, remain most often unnoticed. Does a sound exist if it is not perceived or if there is no medium to transmit its kinetic energy? Is it an individual, a property, a vibration, a sensation, a concept? Do we need an ear to hear? Does a recorded sound become an artifact? These are some of the questions we will try to answer about the traces, audible and inaudible, that sound artists leave behind.

 

Depending on the perspective one chooses to adopt, a sound can have at least three definitions. The dictionary tends to privilege our human perspective of hearing subject: the sound is then an auditory sensation or, to use Michel Chion's definition, an "auditum", in other words "the sound as a perceived sound" whatever its mode of listening*. For physics textbooks, it is a material wave that propagates in an elastic, fluid or solid medium. It is then identified with the mechanical vibration that the wave propagates. Finally, some philosophers consider that sound is neither the wave nor the sensation but the event which, in the resonant object or in its immediate proximity, occurs at the same time as the wave which crosses the medium until it meets an ear (if there is an ear).

Our hypothesis is that these three definitions are not exclusive. For the person who hears it, a sound is an auditory sensation indicating that something has happened somewhere in its vicinity. But he or she may well pay attention only to the sensation itself, for example if what he or she hears is a piece of music or a sound whose richness or beauty makes one forget the source. The physical perspective will consider the vibration, the disturbance that caused it and the medium in which it propagates, but it will also be interested in the way in which the sound waves are perceived and thus in the physiology of hearing, from the eardrum that vibrates to the brain that interprets (acoustics then becomes psychoacoustics). The philosophers adopt still another perspective, that of the ontology. They ask themselves what kind of being is a sound: a thing, an event, an individual, a quality, etc. If, for some, it is a vibration, for others, it is the object of auditory perception, for still others a property of resonant objects, etc. For Casey O'Callaghan, author of an acclaimed book on the subject, "Sounds are events in which a moving object disturbs a surrounding medium and sets it moving in a periodic wave-like manner".**

However, there is a way to reconcile these different perspectives: to consider that sound is not an individual or a quality but a relation; between an event and an ear, between a disturbance and a medium, between a material wave and a sensory system, between two speakers conversing in a closed room, between a pulsar emitting electromagnetic waves, a radio telescope oriented in the right direction and a device translating them into sound waves, etc. For there to be any sound whatsoever, at least two terms are necessary. A disturbance alone does not make a sound, nor does a medium without motion or an ear in a vacuum. A sound is what happens when an event disturbs a medium, or when a material wave vibrates an eardrum or the membrane of a microphone. An ear is only one of the possible terms of the sound relationship. A sound can exist without it, it cannot exist without a cause and a medium. But they are more than mere requisites, sound is no more than the product of their relationship: the way in which a source-energy (the clapper's impact on the bell's body) affects a medium (by varying its pressure) and how it is in turn affected by it. It is impossible to hear a sound without hearing at the same time the medium (air, water, solid state) through which it passes. Let us return to Casey O'Callaghan's definition, quoted above. It is strangely ambiguous. The sound is defined there as an individual, but an individual which can exist only if an object disturbs an environment. In other words, the sound is described as the effect of a relation that does not say its name.
On the condition, however, to think this one as external to its terms. It is the paradox of the relation: it is the product of the terms that it links without being reducible to them. The sound can be the effect of the relation between an auditory system and an air wave without being strictly speaking neither the one nor the other. Its exteriority is only a relative autonomy: it exists only as long as the relation continues. If I move away, the sound disappears as a relation between my auditory system and the vibration of the air, but it continues to exist as a relation between its physical cause and the air medium. 

Let's take a recent example. From June 8 to November 14, 2022, American sound artist Bill Fontana presented - on the fifth floor south terrace of the Centre Pompidou in Paris - a sound installation that allowed visitors to listen to the resonance of Notre-Dame's bells during the cathedral's renovation. The work is called Silent Echoes . " Silent" because the installation left the bells at rest. Bill Fontana simply placed seismic accelerometers on each bell, the tool engineers and seismologists use to measure the speed of vibration propagation in any material. In this case, he uses them to capture the waves that pass through the cathedral's bells. Because these bells never stop vibrating. They vibrate under the effect of the ambient sounds, the wind and the multiple waves that cross the building. These vibrations are too small to be heard by a human ear, but the accelerometers are sensitive to them. They were then transmitted to a computer, where they were processed, composed and spatialized (at Ircam, on the Max/MSP software and in collaboration with a computer music designer, Thomas Goepfer) and then projected on the installation's loudspeakers.

Let us begin by adopting the perspective of the visitor to the installation, on the south terrace of the fifth floor of the Centre Pompidou. He first hears the sounds of the city, those of the traffic along the rue du Renard, the voices and music coming from the Place Stravinsky and the square in front of the Centre, the bells of the Saint-Merri church if he stays there long enough. He then hears, through the 30 loudspeakers placed on the terrace, the resonances of the ten bells of the cathedral, sounds without attack since none of them is struck. He does not hear them all at the same time but listens to their variable superposition, 4 then 9 then 5 then 7, etc., the sounds passing randomly from one loudspeaker to another, which gives the impression of a moving and focused sound space. Finally, he hears the sounds that pass through the bells and that the sensors record with their resonances: the innumerable disturbances that occur around Notre-Dame and that make the air vibrate in which the bells are also bathed. Through the filter of resonances, the visitor hears sirens, engine noises, other sounds that he struggles to identify and hesitates to name, wind, vibrations of stones, crows cawing, etc. Not only the inaudible sounds of the bells but also those, also inaudible, which secretly set them in motion. What the visitor hears, he hears through: through the bells whose sounds have, in a certain way, taken on the shape; through the ambient and multiply vibrating air, the one he breathes but also the one that surrounds the cathedral and that he hears moved on the terrace of the Center.

Let's take another perspective, that of the bells. Since their installation nearly a thousand years ago, they have never stopped vibrating, in other words, they have never stopped being crossed by sound waves that no one could hear, waves that manifested the spectrum, particular to each one, of their resonance frequencies. They sound and reveal their acoustic features without needing to be hit by the cathedral's sounders. We could compare them to eardrums without ears, to metallic membranes suspended in an immense body of stone and wood indifferent to their minute vibrations. It is not necessary that they hear for there to be a sonorous relationship, it is enough that they sound. And it is not necessary that there are living ears for there to be sounds, even if they would then enrich the world with a new relationship.

The sounds installed on the terrace of the Center are the product of a multitude of relations and technical mediations: bells, sensors, fiber optics, computer, software, loudspeakers, plus human ears and brains at different stages of the chain. It is a set of relationships that have become processes of capture, composition and projection.

The sounds that pass through the bells are the result of a three-way relationship between the bells themselves, the surrounding air and the surrounding acoustic disturbances. That these sounds are inaudible by human auditory systems (or by those of other animal species) cannot be an argument against their existence. They exist because the conditions for an effective sound relationship are met.

Bastien Gallet

* The auditum is the sound as perceived sound, without possible confusion with the real source (or the causal complex which is the source), nor with the vibratory phenomena that the discipline called acoustics studies. Unlike the Schaefferian sound object, the auditum is object of all the listenings - reduced, causal, figurative, semantic, different levels of apprehensions at the same time connected and independent - knowing that it is well to distinguish from these listenings which aim it and of which it is the support." Le son, Paris, Armand Colin, 2010 (1998), p. 384.
** "Sounds are events in which a moving object disturbs a surrounding medium and sets it moving in a periodic wave-like manner.", Sounds. A Philosophical Theory, Oxford, Oxford University Press, 2010, p. 61.

Photos © Bill Fontana
Photos © Hervé Veronese - Centre Pompidou
Photos © Centre Pompidou
Photos © Luca Bagnoli