Many mobile devices, specifically mobile phones, come equipped with a microphone. Microphones are high-fidelity sensors that can pick up sounds relating to a range of physical phenomena. Using simple feature extraction methods,parameters can be found that sensibly map to synthesis algorithms to allow expressive and interactive performance.For example blowing noise can be used as a wind instrument excitation source. Also other types of interactionscan be detected via microphones, such as striking. Hencethe microphone, in addition to allowing literal recording,serves as an additional source of input to the developingfield of mobile phone performance.