Hydrophone Sound Experiments
Above video: point of view from camera/ lens as the object being disturbed by water slowly filling an empty sink. The audio and viewpoint abruptly changes when the camera is finally submerged with more subtle minor movements throughout the film. The overhead lighting flickers from droplets on the lens, adding visual vibrations. The sink is the ‘space’ that the object (camera) is occupying. This object begins to shift as the space is interrupted by a constant flowing medium (water). While there is a lot going on in these few recorded minutes – the audio and vibrations are what I’m drawn to. Leading me down the path of investigating audio and vibration in art and their occupied spaces. Ziggy suggested I look into recordings with a hydrophone but I had trouble finding a place to rent one (and the cost of purchasing isn’t a reasonable option for basic experimentation). Instead I opted to build my own as part of expanding my technical intermedia skillset. I looked at a few different DIY tutorials before settling on a tried and tested method by Berlin born techno producer and liveact performer Jörg Jochims (aka Joix), with supplementary documentation from Cosee Tek:
I started out by sourcing the components I would need with some alternatives for what was available in New Zealand. The Piezo discs were easy enough to get from Surplustronics but I replaced the “Stangendichtung Polyurethane” seal for a coffee machines Silicone Group Gasket. The acrylic circles could have been sourced pre-cut but not at the thickness I needed, plus our 3D lab technician advised me it would be difficult to cleanly and accurately drill all the bolt holes. A better option was to source a small sheet of 3mm acrylic and laser cut the discs (plus some extras in case I messed up the first design):
Building the hydrophone: Following the Cosee Tek design, I tried to route the wires through the o-ring but ended up splitting the rubber. I was able to repair the split but found a better option was to run the cables through an additional hole made in the top of one disc. I then made the seals and cable hole leakproof epoxy and silicone.
Testing the sound: At first, I tried recording sound through speaker and amp playback from a tripod-mounted Rode microphone (connected to a recorder) but there were feedback issues as certain settings had to be very amplified for the contact mic to work properly. There was a nice “live reverb” tone but the recordings were a bit lacklustre. I wanted to produced clearer sounds and the obvious answer was just to record directly to the Zoom recorder. It was still good to experiment and learn more about sound setup if I ever wanted to do a live reverb/echo performance.
Creating hydrophone sounds, I looked at sound effect websites like Soundsnap to get an idea of what kind of underwater sounds I could create. I wanted the sounds to be manually produced to compliment the water medium of making my sculptures (and not animal-based or natural environment sonic sounds).
Examples of some of the sounds I produced:
- blowing bubbles through metal straws
- scraping metal objects
- garden hose on different settings
- aerosol can underwater
- diet coke and mentos
- water and fizzing tablets