> Turbine; infrasound
> Bird and flying insects; ultrasound


> 1980: After oil money
> 1987: A straight border (reclamation)
> 1988: Unemployment, divorce, and suicide
> 1996: Down the drain
> 2011: Finally bright?
> 2018: Into the (re)wild


> Body as an active instrument
> First-person listening
> A field listening diary






Written by Minji Kim
Situated listening modes in an ecological place; Sihwa 


I. Listening with Technologies; What we cannot Hear

Imagine we are holding a microphone. What can the microphone sense and how it is different to what we sense? What sound can we hear and what sound can we not? Sound is not only of the human, and undermines human exceptionalism. Everything vibrates on some frequency and is touched by vibration, regardless of how imperceptible to human sensibility this might be⑥. Regarding inaccessible frequency, we can roughly grasp where it is using technical devices. This could be somewhere physically far away or beneath somewhere our bodies hardly access such as under the ground, or under the water. And the inaccessible frequency includes hearing beyond the sonic frequencies of our bare ears. We cannot comprehend the sound of what we cannot hear, but to perceive with the help of a technical device that there is a sonic world where beings interact outside human auditory awareness can be a way to encounter the ecological place.


Turbine; infrasound⑦

An infrasound is an acoustic oscillation whose frequency is low, and under the mechanical range of human hearing. The ear is the most sensitive receptor for sound. If we cannot hear a sound, we cannot perceive it in other ways and it does not affect us⑧. There are many natural sources of infrasound, including meteors, volcanic eruptions, ocean waves, wind, and any effect which leads to slow air oscillations. Manmade sources of infrasound include explosions, large combustion processes, slow-speed fans, and machinery⑨.

Sihwa is an entangled place of machinery and atmospheric infrasound. The hydronic turbine①⓪ of the Sihwa tidal power plant controls the current between Sihwa's open and inner seas while extracting the tidal energy. In research①① regarding the correlation between infrasound and the hydronic turbine, the changes in tidal flow and rotor rotation at the time of the power plant were measured and compared to the levels of noise. The average rotation speeds of the rotor and water wheel during power plant operation were 748 rpm and 43 rpm, respectively. These were converted to frequency. This resulted in 12 Hz and 0.7 Hz①②, meaning that in the process of producing electricity through a hydronic turbine, a water wheel moved by the current generates infrasound. Meanwhile, it is reported that the main frequency of underwater noise generated by the vibration of marine structures is consistent with the frequency of the structure①③. This is an example in Sihwa of acoustic communication between infrasonic and non-humans that humans almost cannot hear. For example, most fish can hear infrasound. They live in acoustically complex environments and are well-equipped to make use of the sound they sense to increase their likelihood of survival. They use their auditory ability for the same purposes as mammals—to detect, locate, and identify their surroundings, conspecifics, predators, and prey①④.

In addition to turbines there are transmission towers, the vibrations of a bridge when the vehicles pass over, cranes at the harbour, ships and many more motors that radiate infrasound. Although there is a case that pollution has been reduced due to tidal power plants, the infrasound of machinery in Sihwa and that of non-humans are conflicted. We realise in this conflict that the ecological consequence of sound is not always clarified directly; we can only speculate the consequence of sound. Sound creates a suspension of immediate understanding through its nonlinear duration, along with its ambiguity. It can be both immediate and run on epic time scales, and the hesitancy that sound creates underpins an epistemological perplexity and vulnerability, one designed with meaning primarily in concrete situations and practices①⑤ .


Bird and flying insects; ultrasound

Constrastingly, ultrasound is a form of mechanical energy that has frequencies above human hearing. The earliest known sources of ultrasound are those emanating from the non-human world. Dogs, birds, crickets, and bats are well-unknown animals whose communication signals extend to the range of ultrasound①⑥.

On the way to the inner shore of Sihwa, forbidden to the public for over a decade, most of the road signs were covered by bushes. Wild dogs crossed the roads of unused pedestrian crossings. Countless species of birds flew in the sky. Sun-mi Park, a resident and activist in the Sihwa area, accompanied me on the field visit. She stopped the car to birdwatch with binoculars. We drove carefully towards the shore, because of swarms of nameless flying insects buzzing around. Overwhelmed by the almost wild world that non-humans had occupied, I arrived at the shore①⑦. Blue-green waves gently broke, accompanied by a harmonious chorus of cicadas. The resonant calls of bullfrogs and the sharp buzz of bees created an orchestral tapestry①⑧. Sihwa is densely inhabited by birds and flying insects①⑨. As the population of benthic organisms decreased due to water pollution in the Sihwa area, birds and flying insects were threatened. However, once public access was prohibited, and after the operation of the Sihwa Tidal Power Plant began, the population of benthic organisms almost completely recovered②⓪. Therefore, in 2009, a total of 2,258 entities of 49 species of resident birds inhabited and migratory birds visited the Sihwa inner sea's side of the land②①.  

Non-humans are above humans in the sense that they communicate in frequencies above our hearing. The ultrasonic layer represents the communication occurring actively in Sihwa that is inaccessible to human ears. Analysing the ultrasound communication of non-humans has been a historical research method of acoustic ecologists (and biology acousticians) in the field of ecology or biology but also in musicology, as Schafer described in his book②②. Any microphone captures plurality ②③. Technology mediates from listening to what we cannot hear②④. However, beyond analysing the rhythm and frequencies of ultrasound non-humans make to figure out their voices, can also more conceptually frame this ultrasound by listening to Sihwa-specific context. This is how to take off the human-centred idea of a place that has a long history of reclamation and artificiality and come to know there are more invisible, inaccessible layers to humans.


⑥   Kanngieser, Anja. 2015. “Geopolitics and the Anthropocene: Five Propositions for Sound.” GeoHumanities, (September). http://dx.doi.org/10.1080/2373566X.2015.1075360.

⑦    The frequency definition of infrasound and others (Minji Kim, July, 2023), Author's collection


⑧ Leventhall, Geoff. 2006. “What is infrasound?” Progress in Biophysics and Molecular Biology 93 (2007) (August): 130–137. 10.1016/j.pbiomolbio.2006.07.006.

⑨   Ibid.

①⓪   Sihwa Tidal Power Plant Turbine Installation (Ansan: Jin-soon Park(KIOST), July 1, 2013), Permission to use photo from Korea Institute of Ocean Science and Technology


①①   Korea Institute of Ocean Science ＆ Technology. 2012. “Development of Techniques for Improving Performance of Tidal Power Generation System.” (December).

①②   Korea Institute of Ocean Science ＆ Technology. 2012. “Development of Techniques for Improving Performance of Tidal Power Generation System.” (December): 204.  

①③   Korea Institute of Ocean Science ＆ Technology. 2012. “Development of Techniques for Improving Performance of Tidal Power Generation System.” (December): 196.

 ①④   Copping, AE, MB Halvorsen, and TJ Carlson. 2011. “Effects of Tidal Turbine Noise on Fish Task 2.1.3.2: Effects on Aquatic Organisms: Acoustics/Noise – Fiscal Year 2011 Progress Report.” Environmental Effects of Marine and Hydrokinetic Energy, (September): 1-2. DE-AC05-76RL01830.

①⑤   Kanngieser, Anja. 2015. “Geopolitics and the Anthropocene: Five Propositions for Sound.” GeoHumanities, (September). http://dx.doi.org/10.1080/2373566X.2015.1075360.

①⑥   Repacholi, M.H., Martino Gandolfo, and A. Rindi. 2011. “Ultrasound: Medical Applications, Biological Effects, and Hazard Potential.” Edited by M.H. Repacholi, Martino Gandolfo, and A. Rindi. 29p.: Springer US.

①⑦   The shore of inner sea of Sihwa (Ansan: Minji Kim, July, 2023), Author's collection



①⑧   Kim, Minji. 2024. “Into the (re)wild.” Ecoes #6 (January).

①⑨   Birds and flying insects in Sihwa (Minji Kim, July, 2023), Author's collection



②⓪   Kim, Minkyu, and Bon Joo Koo. 2015. “The Intertidal Area in Lake Sihwa After Operation of the Tidal Power Plant.” Journal of the Korean Society for Marine Environment and Energy Vol. 18, no. 4 (November): pp. 310-316.

②①   Park, Chi-Young, Ho-Joon Kim, In-Hwan Paik, Jae-Pyoung Yu, Woon-Kee Paik, and Joon-Woo Lee. “Characteristics of Bird Community in Sihwa South Grassland, Korea.” Korean Journal of Environment and Ecology. Korea Society of Environment and Ecology, August 31, 2015. doi:10.13047/kjee.2015.29.4.516.

②②   Schafer, R. M. 1993. “The Soundscape: Our Sonic Environment and the Tuning of the World.” TWO: The Sounds of Life.: Inner Traditions/Bear.

②③   Wright, Mark P. 2023. “Listening After Nature: Field Recording, Ecology, Critical Practice.” 95p.: Bloomsbury Academic.

②④   Ibid.