1. Durée’s

During the people is a colloquial South African phrase equivalent to in company or in front of people. It expresses the gall of an action made more audacious by being done in public. For example, she rolled in the dirt during the people. I’ve been thinking about the significance of this substitution of a spatial context with a temporal one. What reorientation of relation occurs when we consider the people as a duration rather than an assemblage, or when we recognize the people as a spell of time in which we might locate other events.

For the last 35 million years,¹ the continental plate upon which the geo-cosmo-socio-political fixation called “Africa” rests has been slowly and relentlessly tearing itself in two. Its solid crust and lithosphere are splitting and forking, forced apart by events deep within the plate’s viscous mantle. A hole is forming that periodically exposes the planet’s red-hot insides, which quickly blacken as they reach equilibrium with the surface. New land emerges. The Earth vibrates with the immensity of the forces propelling this split. Earthquakes register the cyclical release of this tension. This is called the East African Rift System, and it runs from eastern South Africa, through Mozambique, Zambia, Tanzania, Kenya, Democratic Republic of the Congo, Rwanda, Uganda, South Sudan, Ethiopia, and the Gulf of Aden, where it meets the Arabian plate. Here, it forms part of a larger rift event called the Afro-Arabian Rift System, which crosses the peninsula and runs through Syria, Palestine, Lebanon, and southern Turkey.² All along this skewed axis, the Earth rumbles in tune with an ongoing, million-years-long transformation of this part of the world. A duration. We are during this rift.

2. ongoingness

A short 142 years ago, a volcano erupted on the island of ​​Krakatau, modern day Indonesia. The explosive force of this eruption generated acoustic waves of such intensity that they were registered by weather station barometers in London, a city on another island over 11,000 kilometers away. Apparently unheard in London, the silent waveforms from this eruption are considered the first recorded measurements of infrasound, ostensibly resonating at a frequency below the threshold of human hearing. The furthest distance between two points on the Earth is +-12,756km directly through the center of the planet, or +-20,040 km along the surface of the Earth. These distances are significant because seismic waves, a genre of acoustic waves that travel through the body of the planet, propagate along two pathways: penetrating waves, which travel through the core of the planet, and surface waves, which travel across the crust and lithosphere. Nearness is a relative thing. How these waves travel complicates our notions of distance. They are perceptible either very close or very far from their origins. However, these infrasonic waves fall out of both embodied and technically mediated perception, in the space between their near and far-field effects. Experience, which is to say the intelligibility of these infrasounds, creates an intimacy between the faraway and the right-here through these earthly pathways.    

Geophysicists use infrasound waves to study movement within the planet through the triangulation of arrival times of event-signals extracted from the “noise” of the waveform, allowing them to determine earthquake locations and intensities and issue tsunami warnings and other emergency response data. Seismic data is also used by military agencies to monitor nuclear weapons testing and explosive weapon effects. The largest network of geosonic monitoring arrays is maintained by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). This is important to remember. Scientists process these recordings mathematically and geometrically; in other words, they look at them. But acoustic waves can also be sensed, heard, played.

Infrasound is a distinctly human acoustic concept. For example, infrasound is generally described as having acoustic waves below the lower limit of human hearing. The lowest human hearing level is defined at 20 Hz by the American National Standards Institute (ANSI) S1.1-2023. Innumerable cases of sub 20 Hz perception have been dismissed as psychosomatic signals, nocebo, or placebo. Which is to say, “made up.” Of course, the 20 Hz limit is as much a historical artifact as it is a technical threshold. Writer Sylvia Wynter’s conception of Man2³ as the Western-bourgeois’ biocentric, economically orientated, scientifically defined threshold of subjectivity, helps to sociogenically locate the origins of this limit on perception. Infrasound is subject to all the Wynterian problems attached to this genre of the human,⁴ especially the tendency to substitute a white-western-man in place of any given person and in place of the plurality of human being/becoming. There is power in determining what is imaginary and what is real. Wynter helps to identify what is going on when perception is conditioned by a mediating apparatus (a geosonic monitoring station) and a privileged subject (a geophysicist). Once we know where we stand on this, we can more directly attend to what happens below the 20 Hz threshold. 

Listening exercise one:

[a series of seismic recordings made on the 15th of December 2024 at stations in Mbarara, Uganda, and Kyiv, Ukraine, have been mixed to form this composition] 

On December 16, 2024, the Times of Israel reported that the Geographic Survey of Israel’s seismology department measured a 3.1 local magnitude (mL) earthquake at 11:49 pm the night before.⁵ A viral video on the same night showed a mushroom cloud fireball rising over the Syrian city of Tartus, coinciding with Israeli bombing in the area.⁶ The European Mediterranean Seismological Center (EMSC) and the CTBTO reported a 3 mL event on the night of December 15/16 from a nearby station. Human action is a relatively common source of infrasound. Mining, rocket launches, hypersonic aircrafts, small-arms fire, and other industrial activities are routinely registered as acoustic waves in the body of the Earth. For routine seismic monitoring, these rarely break the threshold of “noise.” They form the everyday violences registered in what we perceive as silence. Scholar Rob Nixon calls these the slow violences “of delayed destruction that is dispersed across time and space.”⁷ The hyper-present, ultraviolence of contemporary military actions breaks this threshold of noise and registers alongside the geological events that scientists privilege as world-shaping phenomena. The CTBTO, in pursuit of its mandate of monitoring nuclear weapons, confirmed that the explosion in Tartus was not a nuclear weapon. Just an extremely powerful conventional one. 

The body of the Earth is the instrument and the transmitter. It’s not that the explosion in Tartus registers at 3.1 mL, rather the explosion strikes the ground with such force that it triggers a seismic event that the Earth responds to by producing an earthquake. 

The vibrations of this quake are transmitted as acoustic waves through the body of the Earth itself. It is the propagating medium, and picked up by any instrument attuned to these frequencies around the world: technical, spiritual, or biological. 

Listening exercise two:

[a series of seismic recordings made on the 30th of November 2025 at the station in Casey, Antarctica, has been mixed to form this composition] 

The 18th-century city of El Fasher sits in the northern part of the ancient cattle herding plains of Darfur. Beginning on October 26, 2025, reports of a genocidal massacre by the Rapid Support Forces in El Fasher began trickling out of Sudan.⁸ Part of the generally under-reported war in the country, this ongoing massacre has played out at the speed of the Rwandan genocide (the last widely acknowledged genocide on the continent). The primary means of murder in this case are assault rifles, FPV drones, artillery guns, and other military grade weapons. A news blackout in the city means there are no longer any direct accounts of the massacre.⁹ Looked at indirectly, through their traces in an infrasonic waveform from the dates of the massacre, these events resolutely fall into the category of noise. Scientists, increasingly aided by AI data processing, are trained to extract signals from the noise of the recorded data. Their signals correspond to events in the seismic record from which a particular kind of information is drawn. A large enough bomb, an earthquake, a nuclear weapons test, a landslide, a tsunami. What scientists consider noise is everything they are not interested in. The indistinct event. The low-amplitude violence. Whatever falls outside the boundaries of their discipline. But noise is only the name we give to the imposition of “everything else.” Within this band of low amplitude waves are the ongoing vibrations of non-spectacular forms of life and death. The persistence of the inaudible. Noise, in this instance, is a mutant form of silence existing in the below-human-hearing acoustic band; this noise is literally what we experience when we say it is silent. Moreover, it is the frequency space in which the imperceptible presences of our present are measured and registered by the Earth itself. The El Fasher massacre continues.

The body of the Earth is the instrument and the transmitter. It’s not that the small-arms fire and FPV drone munitions and artillery explosions in El Fasher are not registered infrasonically; rather, their incessant use and rate of fire register them as subtle modulations in the constant hum of the Earth. Noise. The ongoingness of a genocidal massacre joins the “violence of delayed destruction that is dispersed across time and space, [as] attritional violence that is typically not viewed as violence at all.”¹⁰ 

The vibrations of this noise are transmitted as modulations of the acoustic waves already travelling through the body of the Earth itself and picked up by any instrument attuned to these frequency modulations around the world: technical, spiritual or biological. 

3. Mute/Mutual

The postcolonial condition is marked by an inverted orientation to systems. We are the target of imposed Western sociotechnical systems (of discipline, extraction, dispossession, etc.) and we are also what falls outside the boundaries of those systems. The perceptual frame of Black, African experience is always on the edge of hegemonic in/exclusion. Faced with the violence of racialized and gendered exclusion from discursive and decision-making realms, which, among other things, determine what is or is not real, intelligence operates primarily as the performance of a recognizable intelligence. Recognizable to whom? The ruling class that we can summarize as Man2 and his subordinates. Intelligence means looking, sounding, and acting like they do. Including accepting the limitations of their perceptions of the world while repeating their misconceptions and incompetencies. This is obvious to anyone who’s used an AI chat bot. This is a meager form of intelligence, useful only to those who choose to hide in plain sight. For the rest of us, it is a dead end. The cosmological boundaries of this form of intelligence are determined by embodied relations to the material world. Let’s say, who is listening affects what is heard and what is left unheard. 

It is commonplace that animals perceive and emit infrasonic waves. Whale song resonates across the vast expanses of the ocean. Elephants’ low frequency rumbles travel for miles over the landscape. Birds, fish, etc. The non-human multitude that verify and reinforce the human threshold. They perceive, we do not. This is only true if we accept a definition of we developed at the intersection of those who cannot perceive and those in power. A small circle. Perceivers of the infrasonic world retreat to the margins. 

The threshold of human hearing is generally considered the frequency band between 20 Hz and 20,000 Hz. “However, these thresholds were established at a time when we knew little about very low frequencies,” according to Sabine Meunier, a specialist on psychoacoustics at the Laboratory of Mechanics and Acoustics in Marseille. “All of us can actually hear frequencies below 20 Hz at relatively high levels that are not common in everyday life, with our ears being less sensitive to very low frequencies.”¹¹ 

Every system produces, as a matter of course, externalities, the forgotten life that surrounds it, while bearing the unaccounted costs of the system itself. This is the part of any system that is imperceptible from within its own frame. In scientific grammars, this is registered as black—as in black holes, or dark, as in dark energy. Unintelligible. We perceive the surroundings of a system through producing counter-systems of recognition and action.

Unintelligibility is the sorting mechanism of another form of knowledge which counteracts the hierarchy of recognition. Where intelligence is a pathway to and conferral of power, unintelligibility marks the cosmotechnical limits of that power. “Did you hear that” is not the same as “can you hear that,” but they produce similar results. While the construction of conceptual and mechanical apparatus that might let them perceive what we already do continues relentlessly the significance of that perception remains clouded by the same old colonial impulses. Which is to say the antagonistic boundaries of understanding, the lines in the sand, borders, apartheid walls, etc., that mark the limits of a way of knowing, are entangled with a way of being. 

Instead of aiming to perceive what is imperceptible, we aim to perceive with the imperceptible. As historian and sound theoretician Gascia Ouzounian implores us: “[Listen] with those who are not listened to.”¹² In the mutual knowledge of those things which, should you need to ask, you are not aware of.

Nolan Oswald Dennis is an artist based in Johannesburg, South Africa. Their practice explores the material and metaphysical conditions of decolonization, questioning histories of space and time through system-specific interventions. They hold a Bachelor’s degree in Architecture from the University of the Witwatersrand (Wits) and a Master’s degree in Art, Culture, and Technology from the Massachusetts Institute of Technology (MIT). Their work has been the subject of solo exhibitions at Kunstinstituut Melly in Rotterdam, Swiss Institute in New York, and Zeitz MOCAA in Cape Town. They have been featured in group exhibitions at FRONT Triennial (Cleveland), Lagos Biennial, Liverpool Biennial, MACBA (Barcelona), Palais de Tokyo (Paris), Seoul Mediacity Biennale, Shanghai Biennale, Young Congo Biennale, among others. They are a member of artist groups NTU and Index Literacy Program, research associate with the VIAD Research Centre at the University of Johannesburg, and a member of the Edouard Glissant Art Fund Scientific Committee.