Sound Camera Recordings
Here are some experimental recordings I’ve made with the Lumicon sound camera, which detects modulated light and transforms it to analog audio. I’m having a great deal of fun exploring the city with this device. Its like eavesdropping on a world of sounds that were never intended to be heard.
Urban exploration in Austin at night:
1. Standing 15 feet from an LED message sign, then the camera pans to view a second LED message sign two blocks away mixed with street lights and a neon sign. The distant LED message sign is a higher frequency than the first. The street lights are mellow hum, and the neon is a buzzing sound.
2. Standing about 30 feet from a large scrolling LED message sign at the PromiseLand church. The pattern of words influences the sound.
3. A collage of field recordings from a car trip through residential and commercial areas in central Austin. Highlights include surprising tones from LED taillights, rhythmic popping from a strobe light on a crane, whining from LED message signs, phasey synth-like tones from architectural lighting on a baseball stadium, and weird whooshing static from car headlights. The dominant sound is typical power grid hum from street lights.
4. A newer collage of lightwave field recordings from a car trip through central and downtown austin. Highlights include a night road construction crew with multiple popping strobes, weird chords from an illuminated “W” sign across from city hall, shrill drones from road construction advisory signs, a beeping bicycle headlamp, and more. Several inexplicable things were heard!
Downtown field recording collage
5. I recorded the City of Austin’s big 4th of July fireworks display with the sound camera. Surprisingly it sounds very similar to what you’d expect, but there are some unusual humming and bass noises. I think these are due to the spinning motion of the shells as they fly through the air. I picked out the most interesting sounds from the 20-minute event and collaged them together into a short piece:
Exploring indoor light sources with the sound camera:
1. My CRT monitor, followed by incandescent light bouncing off of a spinning ceiling fan.
2. Light from an LCD monitor mixed with overhead halogen light, followed by a quick examination of gear in a recording studio rack… in order: Alesis Masterlink, Aurora 16, and AMS Delay.
LCD monitor and studio equipment
Optical recordings of percussion instruments:
1. The sound camera is tripod-mounted and focused on glare from daylight through a window as it reflects off the cymbal. The camera is 2-3 feet from the instrument. The cymbals are played with mallets, hi hats are played with sticks.
The sound spectrum of the recordings is concentrated in the low frequencies and extends to about 3kHz. The strongest harmonics are the lowest ones, in the range of 25-200Hz. Overall, the sound seems similar to what you hear if you put your ear very close to the cymbal and play it quietly. In a sense, it is the opposite sound spectrum of the cymbal’s acoustic tone due to the fact that cymbals radiate low frequencies poorly. The shadow of the moving mallet can be heard near the end of the Zildjian ride recording. Thanks to Oguz Erdin for access to his drum collection.
Istanbul Radiant Series 16″ crash
2. Snare drum played with sticks, recorded using illumination from an LED flashlight. The sound camera is about two feet from the drum.
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