- Laurence Libin
Audible signal indicating an incoming call on a telephone, iPhone, or similar device. Landline telephones formerly included two small hemispherical bells rung rapidly in alternation by a clapper driven by a high-impedance electromagnet at a fixed frequency; such mechanical systems still operate in many fixed (not mobile) telephones, although the ringing current voltage might be transmitted digitally over most of its distance. Other fixed telephones use line voltage to produce a beeping, chirping, warbling, or other ring tone electronically. Mobile devices, being fully digital, communicate with their cell base station through protocols that allow ring tones to be selected from thousands of available options.
Furthermore, digital phones can be made to emit a different pitch or tone when each numerical key or area on a touchscreen is touched. These different notes are a basis for iPhone and iPod orchestras (such as the Stanford University MoPhO, University of Michigan Mobile Phone Ensemble, and others in Berlin, Helsinki, and London) in which participants play their parts on their smartphones, which are amplified through loudspeakers worn on the hand or wrist. By means of various ‘apps’, mobile phones can also be made responsive to manipulation in various ways such as breath blown into the microphone, which enables the device to act as a synthesized wind instrument....