A “voice coil” is a type of linear actuator. It pushes or pulls when you apply a voltage to it. The voice coil gives a force that is proportional to the current in its electric coil. To repeat, this type of actuator gives a force, not primarily a velocity or position.
Design and Control of a Voice Coil Actuated Robot Arm …
by John McBean, Mechanical Engineering Masters thesis, 2004.
Basics of Voice Coil Actuators
by Bill Black, et al in PCIM Power Electronics Systems, July 1993.
by George Gogue & Joseph Stupak, G2 Consulting.