The voice coil is an electromagnetic actuator in its simplest form. Voice coil actuators come in two forms; rotary and linear. A linear voice coil will move in a back and forth motion and the rotary voice coil moves in an arc.
Voice coil actuators are ideal when a inertial mass needs to be accelerated quickly or positioned accurately. The control circuit to drive a voice coil is not complicated as a voice coil does not require commutation.
A voice coil is a two-element device. There will be a coil assembly and a permanent magnet assembly. The coil assembly is inserted into the permanent magnet field. When current passes through the coil a magnetic flux field a force is produced at a right angle to the direction of the current. This produces the back and forth motion of a voice coil.