Unveiling secret sounds
In their long-term project Unveiled Presence (secret sounds), the artist duo Natalie Bewernitz and Marek Goldowski explore characteristic sounds and hidden acoustic peculiarities in known and unknown places of the Finnish capital Helsinki. The project makes use of the sound library of laser Doppler vibrometer recordings made in Helsinki in May 2010. A laser Doppler vibrometer can convert solid-state vibrations into a digital audio signal through a light beam and functions as an extremely focused accelerometer, similar to a very long cardioid microphone. Video recordings made of the vibration points were acoustically recorded, thus forming a visual reference to the sound. Based on this library of audio-visual recordings, a single-channel video composition that visualizes the site-specific sound character and seasonal changing of light in the city was developed.