What factors affect motor noise?

Generally speaking our motors are designed to be inherently quiet. This is done through material selection, proprietary design techniques, and controlling assembly processes. However, in your application you have additional factors to consider such as how the motor is mounted in your device, the speed and load at which you operate the motor, and what type of bearing system you use. We can give you some ideas of how to minimize noise, but ultimately you should test any motor product in your device before you finalize your selection.