"SQUEAKeys": A friction idiophone, for physical interaction with mobile devices

We present "SqueaKEYS", a musical instrument application to enhance touch screens on mobile devices. Sound is generated acoustically by the sound of one or more fingers rubbing on the glass surface of a liquid crystal display screen, or the like. In this sense, the instrument is not an electronic instrument, but, rather, a friction idiophone (e.g. in the Hornbostel Sachs musical instrument classification sense). Location sensing on the touch screen is used to frequency-shift the sound onto a musical scale depending on where the screen is rubbed, struck, or touched. In other embodiments the location of the touch is determined with sound localization by way of geophones bonded to a glass substrate, eliminating the need for a touch screen (e.g. to implement the instrument on any glass surface equipped with appropriate listening devices).