page_title: Scratch input
hierarchical_section_title: Scratch input
caption_attribution_description: English: Self-portrait of my right hand doing "Scratch Input" on a chalkboard.
context_page_description: In computing, scratch input is an acoustic-based method of Human-Computer Interaction that takes advantage of the characteristic sound produced when a finger nail or other object is dragged over a surface, such as a table or wall. The technique is not limited to fingers; a stick or writing implements can also be used. The sound is often inaudible to the naked ear. However, specialized microphones can digitize the sounds for interactive purposes. Scratch input was invented by Mann et al. in 2007, though the term was first used by Chris Harrison et al.
context_section_description: In computing, scratch input is an acoustic-based method of Human-Computer Interaction (HCI) that takes advantage of the characteristic sound produced when a finger nail or other object is dragged over a surface, such as a table or wall. The technique is not limited to fingers; a stick or writing implements (e.g. chalk, or a pen) can also be used. The sound is often inaudible to the naked ear (i.e., silent). However, specialized microphones can digitize the sounds for interactive purposes. Scratch input was invented by Mann et al. in 2007, though the term was first used by Chris Harrison et al.
caption: Scratch input using geophones (contact microphones) bonded to each fingernail as a musical instrument. The awful sounds generated by running fingernails down the chalkboard are separately pitch-corrected, resulting in a pleasant-sounding musical instrument.
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