Sound Artist Turns Noise Into Spectral Spectrums

In the world of The Shining’s Overlook Hotel, the Torrance family learned that rooms aren't inert, nor silent. We may overlook this idea when we enter an average bedroom (most likely because the average bedroom isn't haunted), but the thought has not escaped the mind of sound designer, Zach Dunham.

The artist's Acoustic Mapping is an ongoing project that susses out the proclivities of spaces to manipulate sound. His website is host to a series of photographs depicting distributions of sound in space. The photos are grouped, and for each he has given specifications about the frequency of the sounds, the number and placement of speakers, and the key to decode them.

Dunham's work is what might be called process focused. He manages a nice economy that reveals enough about the working constraints of Acoustic Mapping that looking through the pages of photos and explanations of his website provokes you to question the apparently simple and thoughtless way we hear sound. It also encourages the viewer to ask questions about the invisible worlds around us by gathering information about how sound is literally shaped as a medium. His maps point to recent work in [architectural acoustics](http://thecreatorsproject.vice.com/blog/iresonant-chamberi-turns-a-performance-venue-into-a-transformer resonant chamber) and complement the work of other artists like Alvin Lucier and Phil Niblock.

Logistically, Dunham’s setup is pleasantly simple. In order to translate the aural into the visual, you need a way to sense sound pressure and a way to represent it. By mounting an LED light onto a microphone, he is able to link changes in sound pressure to changes in light intensity and, more recently, he has added a color spectrum (processed through Max and an Arduino) so that low pressure is represented by magenta and the highest pressure in red. With this arrangement, Dunham is able to use the light from the LED to represent the presence of lingering tones in various spaces.

"I'm playing a range of sine tones, but only working with one frequency at a time in order to isolate these interferences,” Dunham explains. “In any listening situation there are direct and reflected sounds. As sound leaves the source it propagates outward, reflecting off of surfaces along the way, until it reaches your ears."

What doesn't go into your ears makes its way around the room. Higher frequencies often disappear from the room while the lower ones, like sine tones, tend to accumulate and interact with each other, forming gains and dips in different places around a space. Dunham's maps show where, in a couple of different rooms (his apartment and the loft of a friend), certain frequencies gather and where they disperse.

Acoustic Mapping may not reveal the malevolence of certain old hotels, but the photos go a long way toward showing us how we are surrounded by invisible forces interacting on their own.