Modification of a synth, without a real understanding of how the circuit works, in order to produce sounds not intended by the designers. Individual circuit benders have different techniques for discovering modifications to produce different sounds; one such involves connecting a jumper to ground and then probing various component and integrated circuit pins on the circuit board to see what effect it has on the synth. When something interesting is found, the circuit bender adds a switch or potentiometer to allow the performer to activate the modification. Because of the possibility of destroying the circuit, benders typically experiment with cheap personal keyboards or children's toys such as the Speak and Spell. Given that devices of this type are usually digital in nature, circuit bending often results in glitch sounds, and some benders focus on making glitch instruments. Many circuit bent instruments are found for sale on eBay.