What is "kraakdoos"

The Kraakdoos (or Cracklebox) is a custom made battery-powered noise-making electronic device.

It is a small box with six metal contacts on top, which when pressed by fingers will generate all manner of unusual sounds and tones. The human body becomes a part of the circuit and determines the range of sounds possible — different people will generate different results.

The concept was first conceived by Michel Waisvisz and Geert Hamelberg in the 1960s, and developed further in the 1970s when Waisvisz joined the STEIM foundation in Amsterdam, Netherlands. The kraakdoos is a simple device, based on a single operational amplifier (one of the earliest models to be produced) and a few transistors, and can be easily constructed by someone with a basic understanding of electronics.