Perhaps the most obvious is to increase precision, which is a function of manufacturing and assembly tolerances, gear tooth surface finish, and the guts distance of the tooth mesh. Sound can be suffering from gear and housing components along with lubricants. In general, expect to spend more for quieter, smoother gears.
Don’t make the error of over-specifying the motor. Remember, the insight pinion on the planetary should be able deal with the motor’s result torque. Also, if you’re utilizing a multi-stage gearhead, the output stage should be strong enough to absorb the developed torque. Obviously, using a better motor than required will require a bigger and more expensive gearhead.
Consider current limiting to safely impose limitations on gearbox size. With servomotors, result torque is a linear function of current. Therefore besides safeguarding the gearbox, current limiting also shields the engine and drive by clipping peak torque, which can be anywhere from 2.5 to 3.5 times continuous torque.
In each planetary stage, five gears are simultaneously in mesh. Although it’s impossible to totally get rid of noise from such an assembly, there are many methods to reduce it.
As an ancillary benefit, the geometry of planetaries fits the form of electric motors. Thus the gearhead can be close in diameter to the servomotor, 
with the result shaft in-line.
Highly rigid (servo grade) gearheads are usually more costly than lighter duty types. However, for quick acceleration and deceleration, a servo-grade gearhead may be the only wise choice. In this kind of applications, the gearhead may be seen as a mechanical springtime. The torsional deflection resulting from the spring action increases backlash, compounding the effects of free shaft motion.
Servo-grade gearheads incorporate a number of construction features to reduce torsional stress and deflection. Among the more prevalent are large diameter output shafts and beefed up support for satellite-gear shafts. Stiff or “rigid” gearheads tend to be the costliest of planetaries.
The type of bearings supporting the output shaft depends on the strain. High radial or axial loads generally necessitate rolling component bearings. Small planetaries can often manage with low-cost sleeve bearings or other economical types with low backlash gearbox fairly low axial and radial load ability. For bigger and servo-grade gearheads, durable output shaft bearings are often required.
Like the majority of gears, planetaries make sound. And the faster they operate, the louder they get.
Low-backlash planetary gears are also obtainable in lower ratios. Although some types of gears are generally limited to about 50:1 and up, planetary gearheads extend from 3:1 (solitary stage) to 175:1 or even more, depending on the number of stages.