In 1992, German artist Christina Kubisch, born in 1948 in Bremen, realised the installation 40kHz inside a high bunker as part of the exhibition ‘Amphion, Klanginstallation in Köln und Postdam’ (‘Amphion, Sound Installation in Cologne and Potsdam’). The bunker, chosen by the artist and situated in the Cologne region in Ehrenfeld, was built during World War II on the debris of an old synagogue, destroyed during the Night of Broken Glass (Kristallnacht) in 1938. Kubisch had worked inside a bunker before, a few years earlier when asked to participate in the Metropodium festival (1988) in Amsterdam. She had been fascinated by the labyrinthine shape of the place, and was inspired in particular by the sonic ambiance of the underground: ‘the artificial and sterile silence of total isolation’. 01 In an atmosphere shielded from the surrounding sounds of the city, only the passages of the Amsterdam metro were perceptible through light vibrations. For 40kHz – which relies on just such an atmosphere – the artist uses ultrasonic modules to modify the perception of sonic space, as well as pigments and luminary sources that make traces of ancient inscriptions appear on the wall.

Kubisch situates her work within the analysis of the architecture and history of sites that mark thresholds of aural, visual and tactile perception. Paradigmatic of Kubisch’s approach, 40kHzrepresents the relationship the artist has entertained since the end of the 1970s with ambient waves, fields and matter in particular spaces. Meanwhile the piece’s exhibition context ‘Amphion’, refers to a set of artistic projects that have shaped sound practices in Germany since the 1980s and in which Kubisch is centrally involved. ‘Amphion’ also showed works by Terry Fox and Rolf Julius, whose trajectories have continually intersected with Kubisch’s. Thus two forms of artistic development – individual and collective – that concern Kubisch and the way she has interrogated, among other things, the forms and limits of aural perception, are retraced in what follows.
40kHz is installed on the bunker’s upper floor, and is organised around a long hallway that leads from one side to fourteen rooms, and to three from the other. Kubisch is interested in the site’s sterile and anonymous character, its spaces differentiated only by the numbers above its doors. ‘This alignment of passages without end […] is the space, strictly speaking, of the installation’ she explains 02. Loudspeakers are integrated in gaps above the doors and broadcast frequencies between 10,000 and 15,000 Hz. Kubisch modifies an ultrasound generator – initially sold as a mouse repellent – by manipulating electric tension and creating barely audible high frequencies that appear and disappear at intervals, punctuating the sense of space. This aural punctuation is accompanied by visual marks produced through light sources and luminescent pigments. Darkness alternates with neon and ultraviolet light. Depending on the nature of the light, pigments applied to the walls and around the doors in geometric patterns reveal colours oscillating from light yellowy to intense shades of green. It is the subtley modulation of visual and aural perception in relation to what is already present that situates Kubisch’s work at the threshold the perceptible. According to the artist, ‘any […] intervention of an acoustic or optical order should be minimal and take into account the situation encountered’.03
Kubisch began her artistic career studying painting at the State Academy of Fine Arts in Stuttgart (1967–68), followed by music studies at the Academy of Music in Hamburg (1969–72). 04 Having played the accordion and violin since childhood, she focussed her musical studies on the flute, the piano and composition. She later attended art school in Zürich where she developed an interest in the intersection of artistic disciplines, and at the beginning of the 1980s studied electronic music composition classes in Milan. Kubisch was also interested in contemporary composition, and enrolled in the Neue Musik (‘New Music’) classes taught by Mauricio Kagel at the Rheinische Musikschule in Cologne in 1973 and, the following year, in the international summer course in Darmstadt taught by Christian Wolff, Karlheinz Stockhausen and Iannis Xenakis. This decade was also marked by her encounter with John Cage in New York, where she travelled regularly in her role as a contributor to the journal Flash Art, as well as by exchanges with Phill Niblock, Annea Lockwood, Marian Zazeela, Pauline Oliveros, Joan La Barbara, Trisha Brown and La Monte Young. During these years Kubisch developed her performative practice, combining video with the use of instruments modified through their combination with other objects such as gas masks or thimbles. It wasn’t until the 1980s that she abandoned these practices to turn to installation.