Electromagnetic Field Recordings
Electromagnetic Field Recordings

Electromagnetic Field Recordings

These recording experiments involved putting into practice the some of the techniques explained and developed by Hare (2010) and Onley (2011) regarding the detection and recording of electromagnetic radiation (EMR) and electromagnetic fields (EMF”s).

Hare (2010) describes a technique for detecting and recording the radio wave energy from a mobile phone. He explains that loop antennae of specific measurements resonate at a specific frequency and are therefore capable of detecting different EMF”s from different sources.

Hare (2010) explains:

“Mobiles make use of various bands of radio frequencies to communicate between the mobile to base and the base to mobile: in Europe these include 900 and 1800 MHz (850 and 1900 MHz in the USA and Canada) [2, 3].

The relationship between wavelength, speed of light and the frequency follows the well known formula:
Wavelength λ (m) = speed / frequency = c (ms-1) / ν (Hz)
λ (m) = 300,000,000 / ν (Hz) or approximately: 
λ (m) = 300 / ν (MHz) ….. Equation 1.

So for a mid-range of about 1000 MHz (1 GHz) we get a typical mobile phone wavelength of about:
λ = 300/ 1000 = 0.3 m = 30 cm.”

Using this equation we can determine that to detect electromagnetic frequencies at 1GHz we would need a loop antenna with a circumference of 30cm.

Onley (2011) extends this technique to suggest that with a loop antenna with a diameter of around four feet it is possible to detect and listen to atmospheric sounds such as: ”lightning “whistlers” the “dawn chorus” and other atmospheric energy which may sound like pops.”

In addition to these large scale antennae, Onley (2011) advocates the use of telephone pick-up coils or ”phone tap” devices to listen in on many forms of electromagnetic energy.

In relation to using a telephone pickup coil to record the sounds from a computer Onley (2011) notes:

“As you move the pickup coil around a computer or other micro-processor device, you will hear different pitches and patterns of sounds depending on clock frequency. Press even a single key or execute a command, and you”ll hear new sounds of the computer at work. Laptop computers are especially musical, since there is no AC power involved or metal case to shield the energy emissions.”

Using these instructions I made a 12″ loop antenna and purchased a telephone ”tap coil”. The above recording includes the sound of EMF”s from: a computer mouse, laptop screen, overhead power lines, modem and a smart phone.

With the screen recordings from the laptop and smart phone one is presented with the discernable sound of data whizzing around on the screen, and the scrolling, clicking, tapping of fingers and mice. This appears to be a highly effective way a sonically representing data, as it is effectively the sound of real data movement. These and the other sounds recorded have opened up an interesting hidden sonic pallet, one which is normally avoided or technically cleansed from audio recording devices, and one that appears to represent well our information and data laden society. 

Further sound studies of computer data input, perhaps of specific content, would be interesting in order to capture a sonic/data representation of that action. Also, multiple looped antennae of differing sizes for multiple frequency capture would be interesting. Additionally, further research into the general creative uses for this type of recorded interference would be appropriate.

References

HARE, J. 2011. Simple demonstration to explore the radio waves generated by a mobile phone. [online] The Creative Science Centre: Sussex University. Available at: http://www.creative-science.org.uk/mobile_LED.html [accessed 6 December 2011]

ONLEY, D. 2011. Listening in on… the Sounds of ENERGY!: A updated digest of good ideas first published by CALVIN R. GRAF, USAF engineer,revisited for today”s technologies. [online] Discovery Resources for Radio Communication: Ormond Beach, FL Available at: http://www.qsl.net/k4zra/DR-100.htm [accessed 6 December 2011]

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