The Background Buzz: Listening to electrical substations

In this text accompanying their sound art piece, Poste Transformateur en Ville, Juan Guillermo Dumay and Ruth Oldham explore the interrelations between sound sources in our immediate environments such as the electromechanical, the geophonic and an inaudible planetary hum.

Below our window, on the other side of the street, there is a metal door with bars. A sound emanates from the door. It is a continuous noise, possibly from an electrical source and audible 24 hours a day. This intense and loud drone is part of our acoustic environment – as the wind is, as birds are.

But we are able to ignore it thanks to subconscious and, complex cognitive mechanisms that prioritise certain primary sound signals in our perception. Partly explained by psychoacoustics, this often happens with recognisable ambient noises that are considered unimportant or annoying.

Background vibrations

John Cage suggested that there is no such thing as silence. Our bodies work day and night: vibrating, oscillating. They are the theatre of energy exchanges that we could perhaps hear if we had the means. After visiting an anechoic chamber in Harvard University, Cage observed that

in that silent room, I heard two sounds, one high and one low. Afterward I asked the engineer in charge why, if the room was so silent, I had heard two sounds… He said, “The high one was your nervous system in operation. The low one was your blood in circulation”. ¹

The sensory organs are receptors, sensors, but they themselves produce a very low level noise: they are self-noisy. ² Even in rest, the auditory nerve is subject to spontaneous activity, with a random rhythm. ³ In this respect, the philosopher Claude Mozino goes further than Cage, writing: “the internal rustling of the organism already contains a whole music”. ⁴

Our bodies also receive continuous radiation from the resonant atmosphere, consisting of more or less audible signals – and it is with our entire bodies, not just our ears, that we hear. Vibrations travel through our skin, tissues and bones, informing our perception of the spatial and material characteristics of our environment. The sun sends us solar rays: powerful electromagnetic forces that significantly affect and nourish our planet. Meteorites leave an electromagnetic veil, which some scientists call very low frequency (VLF) radio waves. These radio frequencies can be perceived in certain lightweight materials and objects that resonate at low intensity, such as aluminium foil, dry leaves, or other materials similar to the sensitive diaphragm of a speaker. ⁵

Other research has identified the phenomenon known as Earth’s background free oscillations. ⁶ This term describes the planetary hum which comprises about fifty signals that exist between two and seven millihertz – a frequency that is too low for the human ear to perceive – and of very low intensity. An explanation of the phenomenon has been proposed by Toshiro Tanimoto who suggests that the fluctuation of atmospheric pressure cyclically impacts the earth’s surface:

When the air pressure increases, the atmosphere presses down slightly harder on the ground or sea beneath it. When the pressure drops, the surface gently rebounds. In other words, our planet is like a drum gently beaten by its atmosphere, and at any given moment, some of them will be tapping at the right frequencies to excite the modes that [by resonance] make up the hum. ⁷

Ecologists and biologists have long observed that

living organisms really need random factors in the environment, without which they cannot live. ⁸

They found that turbulence in the environment provides the organs of perception with a minimum level of activity, which is sufficient to keep them functioning. Biophysicist Henri Atlan proposed the concept of “molecular background noise”: a thermal agitation that is irreducible at the chemical level and is an intrinsic element in cellular organisation. Noise is intertwined with life by means of incessant exchanges between the organism and its immediate environment. Therefore, background noise is an essential element of life, as suggested by Agostino Di Scipio in his 2016 essay “Noise and Freedom”. ⁹ We could say that noise generates and conveys vitality.

Substation and soundscapes

The interconnected network for delivering electricity from producers to consumers comprises several stages, of which the distribution substation is the final one before electrical current flows directly into people’s homes. In the substation, medium voltage (primary) power, commonly 11kV in Europe, is lowered to the level used by the general public, 240V (secondary power). This happens by passing the current through a metal coil, consisting of steel, aluminium and copper, within whose magnetic core the energy is dissipated.

The alternating current (AC) runs at a frequency of 50Hz in Europe, Africa and most of Asia, as opposed to 60Hz in North America, South Korea and Japan. These frequencies has defined many things in our society. In the second half of the 20th century, principally in the 1960s and 1970s, many countries began to define their electrical grids and a new European standard was implemented. ¹⁰ In order to avoid distortions, all the machinery and apparatus had to be synchronised to the same basic frequency. This meant, for example, that television used 30 frames per second in the NTSC system in the USA, and 25 frames per second in the SECAM/PAL system in Europe, in response to the difference in electricity’s frequency in those parts of the world.11 In New York City in 1966, artist and composer La Monte Young and lighting designer Marian Zazeela created Dream House, a sound and light installation based on 60Hz continuous sine wave tones and micro-variations emitted by several wave generators. The installation used the frequency of the alternating current found on an electric plug as the referential pitch of the sound emitted by the tone generators to produce a closed environment irradiated by neon lights and low frequency sounds, which could be experienced differently as the listener moved through the room. The installation was in continuous operation between 1966 and 1970, and has since been recreated in various forms and places.

For our purposes, the working frequency of a French substation is about 50Hz. Its sonic emission, centred around this fundamental tone, is possibly the keynote sound of certain parts of our urban environment.12 The keynote refers to the predominant frequency pitch of acoustic space. The 60Hz found in North America would be a B natural, while the 50Hz in Europe would be a G-sharp. The keynote of the soundscape functions – as in a piece of music – as the fundamental note that usually starts and finishes the song, the note that comes and goes, that makes us feel comfortable, secure.

So, we can say that each territory has its own soundscape, the sum of three separate sound sources: biophony, natural sounds; geophony, non-animal and non‑human sounds, often referred to as forces of nature; and anthropophony, sounds generated primarily by electromechanical means, both intentional and unintentional chaotic sounds or noise. ¹³

Each city has, in its background noise, a more or less common sound. Some of those are transversal and are present everywhere and others are unique to a specific place. This may be due to the frequency of the electric current heard as a continuous and gentle noise, but also to the nature of their infrastructure, their topography, the diffused bass noise of motors and traffic, the sonic impact of wind on buildings or vegetation, and many other factors that compose the diversity of the soundscape.

As well as their role in constituting the keynote of our urban environment, the sound emitted by electrical substations also forms localised “soundmarks”. The soundmark, or acoustic landmark, is a notion proposed by Murray Schafer, who noted that

once a soundmark has been identified, it deserves to be protected, for soundmarks make the acoustic life of a community unique. ¹⁴

The sound emitted by substations has the characteristic of being a complex sound, endowed with a sustained and pedal-like energy, randomly modulated by micro variations, low, hoarse sounds, strange and familiar at the same time. This sound, recorded both at midnight and midday, became the subject of the piece.

Making the sound piece, recordings and fiction

After the initial recording of the substation situated across the street, we began to realise what a dense network they formed. Walking in and beyond our neighbourhood, we started noticing the discreet yet distinctive metal doors all around, each slightly different from the other. Some of the substations are in small detached buildings, others are tucked into the ground floor of a public building or a residential block. As one walks along the pavement, a metre or two before arriving in front of one of these doors, the hum suddenly appears, intensifies, then dies away as one passes by. Our movement through the city is punctuated by the repetition of this gentle hum that emerges and fades away in a few seconds, or a few footsteps.

Standing outside the different substations, listening, we wondered where the coils were situated. When they were close to the door, the level of sound was loud enough to record. The best time to record was at night, when the streets were quiet. We recorded with two conventional cardioid microphones positioned at 90 degrees (known as X-Y position) to have a stereophonic image of the space around the substation, and also used contact microphones, which were positioned on the surface of the metal door itself. The sound piece has been created with both types of recordings: aerial and contact. This means that in the final piece we can hear the dry and concentrated from the contact mic, and the rich and open sound image from the microphones placed close to the source but far enough away to capture many other sounds in the street.

This sound art piece revisits the genre of radio art and deals with the existence – discreet and alienating – of the urban electrical substation, whose sonic presence exists alongside the buzzes and hums of street lighting and vehicle engines. The piece is about walking in the city as well as the interplay between our thoughts and emotions in our acoustic environment.

The text is spoken by two voices – one female, one male – speaking English and French respectively. After drawing attention to the presence of the vibrating metallic doors dotted around the city, the main (female) voice says: “I like to walk close to them, and I leave them behind me, knowing that they are not following me…” Later, the male voice appears. Following as a canon, it forms a duologue, sometimes adding meaning or French interpretations.

In the third part, the female voice says: “When I wait at the traffic lights, the sound of the car engines relaxes me, I feel serene”, evoking an idea explored by Yasunari Kawabata in his novel The Sound of the Mountain that the aural atmosphere, as a mysterious and invisible phenomenon, could affect the mood and mental health of someone. ¹⁵ Shingo, the central character of the novel, is constantly confronted by sounds and noises that drive him to madness. David Toop recounted an anecdote, that originally came from Schafer, about a woman who had tried to commit suicide.

A low throbbing noise was causing her distress. Nobody else could hear any such sound, but the woman’s consultant made tape recordings and during the analysis of the tapes discovered a strong peak in the 30 to 40Hz range. The origin of that unsettling noise was pinpointed to electricity transmission sounds. ¹⁶

Conclusion

Our sound piece is in a way an acceptance of something that could be perceived as negative within our everyday soundscape. We wonder if the hums and buzzes of the electrical infrastructure might provide structure and even reassurance.

Schafer’s nomenclature of “lo-fi” and “hi-fi” designates as lo-fi a low-quality soundscape, which corresponds to the audible environment of a contemporary city. In a lo-fi soundscape, he says, individual acoustic signals are obscured in an overdense population of sounds[…] Perspective is lost […] there is no distance; only presence. There is cross‑talk on all the channels, and in order for the most ordinary sounds to be heard they have to be increasingly amplified. ¹⁷

In this regard, the sound atmosphere of the street nearby becomes a familiar and reassuring habitat for the protagonist of the sound piece. The alienation caused by a supposedly harassing acoustic environment becomes something normal, familiar and, in a way, positive. This is explained tacitly by the human capacity to adapt to difficult situations, and the need, at a different level, of some background noise to the existence of life.

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