PC speaker

I've been reading about outputting PCM audio through the internal PC speaker using "Pulse-width modulation". If I understand correctly, this is acheived by retracting the speaker cone before it has a chance to fully extend. My question is now this: would it be possible, by spending all CPU resources on this task, to keep the speaker cone in its current mid-extension position, by rapidly (as fast as the CPU will allow) toggling the current to it?

>>16
With LED backlit displays, turn down their brightness, then wave your hand in front of them.
That is not a valid use case.