Adventure in the dirac delta

16th of july sheffield, see http://lurk.org/placard/

Two years ago I asked friends and colleagues to record some impulse response recordings for me. An impulse response is a way of capturing the acoustic characteristics of a space. This is often achieved by bursting a balloon or shooting a starter pistol and recording the sound in the space. Balloon bursts and gunshots produce a very short loud spike, ideally containing an even distribution of audible frequencies. What you hear as the balloon bursts or the gun fires is actually the behavior of the acoustic energy in the space as it dies away. Using a process called ‘convolution’ the impulse responses can be combined with other sounds to give the appearance that these happen in the space where the impulse response was originally recorded. For this project I have chosen four sets of impulse responses, recorded by Sonia Matos and Florian Hecker, Tony Myatt, Mat Steel, and Christophe Charles. Depending on which headphone socket you choose, you will hear the sound as if it is on one of the four places. In some cases, for example the recordings made by Christophe, impulse responses were recorded in different parts of a building; whereas the impulse responses recorded by Tony Myatt are different attempts to capture a single fixed position. Throughout the performance I will switch between different impulses taken in these spaces; in some cases this creates a small audible click. The size of the numbers In the photos below indicates the amount of change you can expect as impulses are changed.

here i have included 4 short sound files. these use a rectangular waveshape with random pitch variation convolved with some of the impulses.

Thanks to Sonia Matos & Florian Hecker, Tony Myatt, Mat Steel and Christophe Charles for their help and cooperation in this project.

1. La Palmita Valley, recorded by Sonia Matos & Florian Hecker

listen

A hundred kilometers off the Atlantic coast of Morocco and the Western Sahara one can find the small island of La Gomera. Here lies hidden, in the interior of the island, the village of La Palmita in the municipality of Agulo. In this remote valley, situated in the north part of this island, and that once harbored a thriving agricultural community, one can experience a series of intense echoes and reverbs. These recordings attempt to dramatize the valleys physical and sonic milieu or rather present them as inseparable entities. Recorded 05.11.2007 in the La Palmita Valley, La Gomera, Canary Islands[1] using a SoundDevices 702 digital recorder and 2 x DPA 4060 omnidirectional microphones with Rycote lavalier windjammers. GPS Data aquired using a Garmin GPS 38. Altitude set to zero at sea level in Valle Gran Rey. [1] N28 10 896 W017 12 109, Altitude 1836ft; N28 10 895 W017 12 110, Altitude 1836ft (GPS update failure); N29 10 624 W017 12 595, Altitude 1973ft.

2. Cropton Forest, recorded by Tony Myatt

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In 2007 the Campaign to Protect Rural England (CPRE) published a series of Tranquility maps of England. These mapped England according to disturbance from noise or visual intrusions produced by infrastructure such as motorways and major roads, urban areas and airports. The maps show the extent of noise intrusion in the early 1960s, early 1990s and 2007 and reveal increases in noise levels since the 1960s that have left few quiet outdoor locations in the UK. While some quiet places still exist, I took the opportunity to capture the audio impulse response of one; at the centre of Cropton Forest in the North Yorkshire Moors. This is a densely wooded and hilly area that has a subtle reverberation characterized by sound reflecting from tree trucks and echoing through the valleys of the forest. The recordings were made between 4 and 5am to avoid sounds made by forest workers and the dawn chorus. Impulses were recorded at 96kHz sample rate and in Ambisonic B format. This recording format captures three-dimensional soundfields and can be used to recreate three-dimensional sound playback. Convolving impulse responses with other sounds notionally “locates” the sound where the impulse responses were made. I recorded several impulses at different distances from a microphone positioned in the dimly lit and silent forest as the sun rose.

3. Singuhr, recorded by Mat Steel

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Die singuhr - hoergalerie ist seit über zehn Jahren der zentrale Ort für Klangkunst in Berlin. Über 60 Ausstellungen audiovisueller Kunst realisierte das national wie international einmalige Projekt – Kunst, die sich der eindimensionalen Zuordnungen konsequent verweigert und die individuelle künstlerische Positionen im Spannungsfeld von Musik, Bildender Kunst und Medienkunst reflektiert. Das Spektrum des Galerieprogramms reicht von Klangobjekten und kinetischen Skulpturen bis zu reinen klingenden Räumen, von audiovisuellen Inszenierungen bis hin zu physikalisch temperierten und bildnerisch gestalteten Räumen.

4. Abbaye de Fleury, recorded by Christophe Charles

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The Abbaye de Fleury was founded in 630 in Saint-Benoit sur Loire between Orleans and Sully. It is a Benedictine monastery standing on a flat land not far from the river, where 38 monks still live and work. The nave (73m x 17m) and the tower of the abbey were built in the 11th century in roman style, the rest is in Gothic style from 12th century. The nave and transept have a high ceiling (20m) and big windows on each side which make the whole space very bright. During the Easter feast the abbey is full of people who come to listen to the monks chants, but it is very calm during the year, and visitors can experience a heavy silence where every single little noise is magnified by the reverberation of the huge architecture. Once emitted, the sounds seem to fly or flutter around. I was lucky to find—during the Summer of 2010—a moment when I was alone in the Abbey. I recorded sounds of hitting stones and chairs from different places at different distances from the microphones of a Zoom H4 in the nave and the crypt.

many thanks to:

for inviting me to take part in this project