Arising from the initial research we performed on the ultrasonic acoustic emissions – and hence possible communication – in plant roots, that materialized in the video-work Dialogue with 02.205, (reference1) we (Laura Beloff & Christian Brems) decided to continue this exploration. This now with the overarching goal of creating a form of live installation where the roots acoustic emission will be registered, amplified, down-sampled and played back to an audience so that they can have a physical experience of the possible sonic communication within plants.
The initial studies stem from the relatively new scientific field of bio-acoustics; “the branch of science concerned with sounds produced by or affecting living organisms, especially as relating to communication.” (reference2) Research herein has found that plant roots emit irregular high frequency clicking sounds, UAE’s (Ultrasonic acoustic emissions), in the humanly inaudible sonic range between 20-300 kHz. (reference3, reference4). After having successfully recorded some of these UAE’s for the video-work, our new challenge is now to create a system for live down-sampling these clicks into the human range of hearing below 20 kHz.
INITIAL TESTS / COLLABORATIONS
We initiated an experimental collaboration with students from the Technical University of Denmark (DTU) in the Acoustic Technology department. We organized the collaboration in order to explore the possibilities of creating a Hardware based DSP (Digital Signal Processing) solution where the recordings of the tree roots will be both down-sampled and amplified within a DSP unit. In order to customize the DSP for the frequency range of a specific set of roots clicking sounds, we measured these through the use of an Oscilloscope (left picture). The DSP is also used within bat-detectors (right picture) so we modified one of these towards measuring plant roots, in order to test its capacities. The reason behind selecting the chili plant for these experiments came from Monica Gagliano’s investigation of these particular plants responsiveness to acoustics (reference5)
Oscilloscope and Bat Detector attached to a chili plant
GROWING TEST SUBJECTS
We have meanwhile started growing a range of plants whose roots, according to our research, should be fitting for creating and receiving sound. The two types that are reemerging are both corn-roots and pea-roots (pictured below). We aim at creating a wide array of different roots that we can start testing on when the technical system is complete, so that we can start categorizing the individual results – and verify or falsify their sonic emissions.
young pea root
Finally we have started a branch of the investigation into the acoustic capabilities of fungus mycelium, the roots of mushrooms that has in resent research been found to act as a communicative network and ‘wires’ between trees and even whole forests. (reference6) These new findings sparked an interest for us in terms of whether the mycelium itself is able to create kinds of acoustic emissions, so we have initiated different mycelium growing samples (image below) to investigate this.
mycelium roots in petri dishes.
These investigations and experiments started within Hybrid Matters project and are also documented at Hybrid Matters website_ here.
March 2017 – short update on recording the plant roots.
We have developed a system that enables us to easier record the roots:
We are mainly focused on roots of trees (fir tree) at the moment.
Also the aesthetics for the piece are gradually under process:
Currently – we clearly receive clicks from the roots, however they are more in the audible range and not so many in the ultrasonic range as we originally expected. There is a clear difference in the clicks between living roots (many clicks), recently cutted roots (less clicks), and no roots (no clicks) > In other words we have debugged away the possibility that clicks come from environment and not from the roots. Now the question is what to understand from these clicks?
Shortly on our set up: We are using higly sensitive piezo elements that are connected as dual microphones, a sound card and some filtering softwares, etc. We are hoping to be able to minimize the hardware in the future.