Isospatialisation (Frame 1)
Isospatialisation (Frame 1) is a conceptual, mixed-media artwork centered on the complex, multi-faceted relationship between a number of varied, yet interconnected, elements: Sound, Air, Atmospheric Pressure, and Weather. Isospatialisation (Frame 1) involves the induction of geographic representations, isothermic formations, and atmospheric pressure maps as vehicles for sound spatialisation. The translation of meteorological maps into descriptors for controlling the movement of sound is based on both meteorological and acoustic theory. Air pressure, and thus ambient temperatures, play an important role in how sound waves travel through their given medium, air, and thus within Isospatialisation (Frame 1) the relationship between pressure maps and sound directionality is considered in a more exploratory manner. The listener, placed within an octophonic surround sound formation, is allowed entertain the subtle relationship between atmospheric pressure and sound. The aural identifiers that are heard, directly correlate with the temperatures of each map, implemented through the utilisation of additive synthesis techniques, while the direction, movement, and placement of sound is simultaneously informed by the isothermic maps that are shown in each image. The relationship between sound and weather may also be seen as a metaphor, informing the listener towards a greater sense of inclusion and connectivity, especially when concerned with the totality of the ecosystem.
Puerto Rico, Greenland, Iceland
United Kingdom, Antarctica, North America
|Country||°C||Speed of sound (m/s)||Audio Wavelength (m)||Sound frequency (audio) (Hz)||Frequency (sound) (Hz)|
From top left: North America, Antarctica, Iceland, Puerto Rico, United Kingdom, Greenland
For my final unit of study I decided to develop a surround sound installation that is informed and driven by a static image. The initial idea was to design a set of images which would act as descriptors for determining the localisation of a sound within a surround sound environment. However, during the research and development period, I expanded and evolved my initial idea. Instead of creating abstract, aesthetically pleasing images to generate personalised sound spatialisation, I decided to use isothermic, or atmospheric pressure, maps to inform these tasks.
Atmospheric pressure, and thus temperature, play an important role in sound, as they determine the speed at which sound travels through air. Temperature also determines the ratio of the length of any sound wave with respect to its frequency. Based on these facts I have chosen to use six temperatures, based on six different geographical areas, to generate both sounds for my installation, using additive synthesis techniques, and isothermic maps for localisation information.
The geographical areas that I have selected are: Antarctica, United Kingdom, Puerto Rico, North America, Greenland and Iceland.
To generate a unique sound for a particular area, I had to convert the specific temperatures as given by each map to the Speed of Sound (c) that the temperature would afford. I then computed the Wavelength (λ) of a 1000HZ tone at this Speed of Sound which then was converted to a Sound Frequency (audio) (f). The formulas for conversions I found on sengpielaudio.com:
c = 331.29 m/s at 0 degrees Celsius
Formulas and equations for sound:
c = λ × f
λ = c / f = c × T
f = c / λ
When I converted all the temperatures to sound frequencies, I then implemented them using an additive synthesis patch that I developed using Cycling’ 74’s Max/MSP software. To accompany the sounds, I created a visual representation of isothermic maps and these determined the localisation of the sound.
For the exhibition I used eight speakers located in an octophonic surround sound set-up. To display the visual representation of the process of localisation I have used a video projection. In addition I have printed the images of each individual map, with their unique isothermal pattern, so I may present the images in their usual, physical, static representation.
Due to a lack of knowledge of physics, during the calculation of the equations, I had to dismiss some important aspects that effect the way sound travels through air. Such aspects that were dismissed were humidity, wind speed, elevation above sea level, etc. I made the assumption that the temperature of the air was the only factor in determining the speed of sound.
In the near future I am determined to expand this project further buy including all the elements of air pressure that have an effect on the way sound travels through its medium, so as to develop more precise and unique sonic identifiers for a particular geographical region on any given day. Moreover, there is also a possibility to make this project a real time sound installation by directly feeding live meteorological information into the system.
Sound lines test with coloured background