Page 46 - I have a dream

THE ENGLISH SCHOOL MA GA ZINE 2022

BIO-DATA A simple description of the term
‘Bio-data sonification’ is the use of
SONIFICATION: technology to turn real-time electrical
signals of living organisms (usually
THE VOICE OF plants) into sound. This project was

inspired by devices like ‘Plantwave’
THE PLANTS which, seemingly magically, produce

By Panagiotis Filalithis 7R music out of any plant.
Of course, the plants themselves do not produce music. What
goes on in plants that allows the conversion of signals into music is
electrical impulses. While plants do not have a true nervous system
like many animals, they can still generate such impulses, called
action potentials. This happens whenever the concentration of ions
(charged particles) is different between the inside and outside of a
plant cell, creating what is called an electrochemical gradient. This is
managed by specialized protein channels and pumps located in the
cell membrane of plant cells, and this process happens throughout
the plant. Unfortunately, scientists are still not quite sure about how
these electrical signals are “utilized” by most plants, but they believe
that these signals play a role in regulating physiological processes,
especially those that allow plants to respond to environmental cues
like light, touch and gravity. However, it is known that electrical
signals are involved in bringing about rapid movements in some
plants. A well-known example is the carnivorous plant, Venus
flytrap, which responds to touch by insect prey by snapping shut its
“mouth” (1).
Putting the plant biology aside, it is time to see
how we have used the naturally occurring
A Venus Flytrap and a zoom into the trigger hair sensor that senses touch
stimuli and initiates closing. electrical signals to generate sound and
A schematic of the circuit used consequently music, with the use of electronics
and programming.

Method
1. A 555 timer circuit is connected to the probes to measure the
resistance/electrical conductivity of the plant.
2. This circuit (formally known as an ‘astable multivibrator circuit’)
expresses the resistance across the probes as the time period of a
square wave, which we read and measure using the Arduino board.
3. The Arduino measures the time taken for one cycle of the wave.
The time taken is proportional to the resistance of the plant.
4. The arduino is programmed to read 10 time period samples. It
Legend
calculates the mean and standard deviation of the samples, and
calculates the pitch and duration of a note using those values
respectively.
5. A midi packet is produced which consists of the pitch and volume,
which is sent to the computer via USB transmission. 2 types of midi
science packets are used, one to turn on the note and one to turn it off. This
midi packet is essentially what determines the sound produced.
6. The resulting audio is generated using Python code.
7. To make a more fascinating sound, the audio can be recorded and
then be edited using other software (e.g. audacity).

44 ‘music’ generated by
You can hear the

our cactus via the
following
QR code:

Reference: (1): Jabr, F. (2010) ‘Plants cannot "think and remember,"
but there's nothing stupid about them: They're shockingly sophisticated’,
Scientific American, 16 July.
Available at: https://blogs.scientificamerican.com/observations/plants-cannot-
think-and-remember-but-theres-nothing-stupid-about-them-theyre-shockingly-
sophisticated/ (Last accessed: 14 April 2022)
Our circuit (built on the white breadboard) and Arduino (blue board on the Credits
left) connected to an oscilloscope. We did this to verify that the circuit Circuit and code: Andreas Nicolaou 7W
works and the resistance of the plant is detected. Equipment: Dr Leigh, Physics Dept., Andreas Nicolaou 7W