Fingerpickin’ is an etude written by Edgar Berdahl for inaudible, vibrotactile stimuli only. It was created through the recording of audio signals from a hexaphonic guitar pickup, which had a separate piezo sensor for each string. The string signals were then pitch-shifted down by two octaves in order to enhance the touch sensation. Finally, the signals were low-pass filtered with 18 dB/octave filters in order to help make the sound of the SDVAA less audible. Specifically, the cutoff frequencies 190 Hz, 140 Hz, 105 Hz, 90 Hz, 66 Hz, and 50 Hz were used. The video can be viewed below:



The signals tended to look like this: