Inertial axis fusion device, system and method

A device includes one or more inertial sensors and fusion circuitry coupled to the one or more inertial sensors. The inertial sensors, in operation, generate inertial sensor data with respect to a plurality of axes of movement. The fusion circuitry, in a polar fusion mode of operation, applies a plurality of polar rotation operations to the generated inertial sensor data to rotate the generated inertial sensor data onto an axis of the plurality of axes of movement. A fused data signal is generated based on a result of the plurality of polar rotation operations. The plurality of inertial sensors may include bone-conduction sensors.