While gyroscope and magnetometer data are static and can therefore be used to continuously control sound processes (a value can be mapped directly to a slider), this is not the case for accelerometer data, which only have values when they are moved. However, with the sensor at rest, a constant, non-zero value appears on the accelerometer's Z axis, due to terrestrial gravitation. In the absence of a magnetometer, this offset can be projected onto the XYZ axes to estimate static rotation angles, as with a magnetometer. In the beginning of [to do] Babil-on, this offset of acceleration due to gravity, projected onto the vertical axis of the hand, provides a continuous controller of a sound effect (in this case, the transposition and gain of a voice sample).

Babil-on, with Richard Dubelski, CMMR2013, Marseille France, October 2013.