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?

>>8
That's what PWM does - it generates a quasi-analogue signal based on the ratio of "on" vs "off" time. The more "on"-time, the further the cone is pushed out.

It can sound pretty impressive on a proper PC speaker. It will sound like crap on the piezoelectric buzzer that is probably soldered onto your current motherboard.