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.