afaik, only 4-pin fans on 4-pin fan headers allow this kind of adjustment. 99% of the times only the CPU fan has 4 pins.

For 3 and 2-pin fans you need to get a fan resistor (cheap, available in 2-3 fixed voltages thus you have 2-3 fan speeds depending on what of the bunch you decide to mount, the less the voltage, the lower the RPM, the fan usually can't operate at all below 5 volts) or a fan controller (more expensive but you can fine-tune it and it's the best choice if you have a ton of fans in your case).
Either can be made from scratch if you have some soldering skills and google a DIY guide on the Internetz.

And/or a quieter fan, of course.