IS the Hummmmmmm caused from fan speed controllers BAD for my fan?

Anyone out there had a fan crap out prematurely because they used a fan speed controller? My fan is a Hydrofarm active air and ive read that the hydrofarm speed controller will work with my fan. Its doing what i need it to do but im worried the humming means something is off and im killing my motor. I also dont need another fire risk. Any help would be greatly appreciated. thanks.

So I called the guy from hydrofarm and he said that any humming is really bad for the fans motor. But he said that there is such a demand for them that they have to sell them.