Yeast Lab: the sound of microbes & magnetic fleas

Last week I had a wonderful day with Simon Park, recording the sounds of the microbiological laboratory at Surrey University. Simon, an expert in microbiological luminescence, had very kindly set up a number of cultures: a conical jar of yeast and two petri dishes of other luminescent microbe colonies. The cultures are kept in a series of incubator rooms set to different temperatures in order to aid the growth of microbes. The room set to human body temperature is breathtakingly warm; I had no idea that I was this hot.

This initial visit to the lab was a kind of acoustic reconnaissance: lets listen to what is there to hear. Simon showed me the various machines used to stir and agitate the liquid cultures. This includes the ‘Magnetic Flea’, a seemingly uninteresting, elongated plastic covered magnet, visually not unlike a suppository. However, when the flea is put into a jar placed on a spinning machine, it begins an untidy clangorous choreography, as it rattles against the glass walls of its container. Finding equilibrium, it produces a distinct pattern of movement and sound, each magnet composing its own percussive stir: unique to that jar, that flea, in that moment and that position. The patterns continually evolve and change like listening to waves fall onto the shore, a sonic equivalent to the visual patterns of growth produced by the microbes in the petri dish.

We spent hours (and I do mean hours) trying different jars, different fleas, different microphones, and different spinners. Some of the machines allow the speed of stir to be varied, so that the jars can be ‘played’ like a musical instrument. And whilst some machines spin to stir, others have a gentler shaking action, like the clichéd motion supposedly used to swill brandy around the bottom of a glass.  I recorded many variations of instruments, jars and microphones to capture a canon of growing percussive patterns.

In one of the incubator rooms I placed contact microphones against the sides of a conical jar containing yeast. On the surface of the solution you could see small eruptions of gas as the yeast feeds, digests and expels. In appearance it is not unlike looking through a telescope at the surface of some gaseous planet. It is interesting that visually we often find the microscopic and macroscopic interchangeable: so what would be the audio equivalent? I suppose the contact microphone may be seen as a form of aural microscope: delving beneath the surface to listen to the very substance of things, bringing the tiniest sound closer and making it available to the ear.

Through the glass membrane of the conical jar, the snap, crackle and pop of yeast digestion is audible, although the contact microphone also picks up the vibration of the incubators heating system  travelling through the metal shelving system. This metallic hum adds a laboratorial ambience to the sound here, (I have reduced it slightly in post-production, so as to emphasise the sound of yeast). The drone of environmental climate control could perhaps be called the ‘keytone’ sound of the laboratory (and of the archive; a soundscape I have also explored). R Murray Schafer described a Keynote sound as ‘often not consciously perceived’ but ‘heard continuously or frequently enough to form a background against which other sounds are perceived.’ In the laboratory the hum of temperature control pronounces an acoustic stasis, the pulsing sound of time standing still.

A hydrophone sunk into the solution, is surrounded by the digestion of yeast, although again the ambient sound of the laboratory is also present in the mix: this time it’s the voices of people preparing to experiment. In order to get a larger hydrophone in on the action, we decant the yeast to a metal pan and notice (through the microscope of contact microphones) a change in the acoustics resulting from the metal skin of the pan. Another experiment, set-up quickly by Simon, involved two conical jars and a rubber tube. By gently stirring one jar full of yeast, the gas escapes up the tube into a jar full of water, producing quite delicious bubbles of effluent.

The yeast songs have their own pattern, as the microbes consume all available oxygen and food, the static crackle of their existence is extinguished. There is the possibility of producing a spatial and acoustic bell curve, through which could be heard the life cycle of these microbes, their multiplication, peak and extinction: a microbiological soundscape, beginning with silence and returning to it.

one of ten: unpredicted duets and the company of rivers

On the 31^st October, artists, musicians, dancers, writers and other creatively inclined individuals and groups from the Winchester district occupied the stage and architecture of the Royal Theatre, Winchester. Unlike the worldwide occupy movement, this occupation was curated by Trisha Bould at the invitation of the theatre and was part of an opening event for the Ten Days Across the City, arts festival. Beginning at six and ending at the stroke of midnight, Map, Plot, Plunder and Possession led its audience behind the scenes of the theatre, into the normally concealed backstage areas of the building.
As part of the event, I composed a cycle of three soundscapes for the auditorium and a sonic river for the public address system. The cycle included soundscapes from the winnall moors sound walk project and Winchester Cathedral, that had been specifically re-composed for the site of the auditorium. In between the two soundscapes, I inserted a percussive interval created by evoking sounds from the lighting and scenery rig of the stage; swinging the descended rigging and occasionally hitting it with a toy xylophone mallet.
The soundscapes were intended to inhabit the acoustics of the theatre and act as a consistent cycle of sound spaces that would come into contact with other acoustic events taking place during the evening. This included; a rehearsal of a song by the Winchester Community Choir from the theatre circle; and the indeterminate composition Copy Rite by Hossein Hadisi and other members of ACE (Avant-garde Composer’s Ensemble).
The choir began their rehearsal in the percussive Interval, before being acoustically repositioned into the soundscape of Winchester Cathedral, the opening of the Cathedral gates, the organist at practice. Perhaps most pleasurable was the choreographed pile up of rehearsal as the community choir’s preparations collided with the Pilgrim school rehearsing in the Cathedral.
In Copy Rite, Hossein Hadisi and the other members of ACE (Sam Cave/Guitar; Tom Green/Piano & Ignacio Agrimbau/Gyil & Hulusi) moved around the theatre between pre-arranged sites within and without the auditorium: a piano in a stairwell, a guitar on the first floor of the atrium. The sounds of the auditorium were fed back into these satellite positions, all the musicians responding to the sounds, acoustics and other visual events occurring around them. Both the choir and Copy-Rite, created some rather unrehearsed collisions with the continuous cycle of soundscapes.

The peripatetic music of ACE, mingled not only with its disparate musical parts, but also the acoustics of the theatre and the patterns and dynamics of the entire recorded and existing soundscape. The sonic river, composed entirely from the sounds of water from winnall moors, leaked, flowed and dripped into the acoustics of the architecture. In the front of house speakers the water generated small wet, but distinct pockets of sound. In the non-space of the corridors the speakers created a ventriloquial soundscape, the echoic drips evading location. In the atrium, the dripping of water echoed the pluck of guitar strings, the river seeming to rain down from the heavens, although the speakers were actually located. A fragment from this unpredicted duet appears on the winnall moors sound walk blog, along with a section of the unaccompanied sonic river.
All photographs by kind permission of David Gibbons.