Induction Motor speed control idea and question?

[cimmo]

I have recently built a standard triac chopper circuit to provide speed control of a permanent split capacitor induction motor driving the fan in a rangehood. It works well except for the hum (that was not a surprise).

My question is: if one full mains cycle was fed to the motor in every x number of cycles (with switching at the zero crossing point), would this drive the motor without significant hum?

Using optocouplers and a picaxe, I think this pseudo PWM control would work, but I am interested to hear any ideas yay or nay on the proposal?

Edit: Further thought: intermittent triggering of a zero-crossing solid state relay?