When a machine is subjected to a noise-reduction program, bearings are normally involved. Even when bearings are not generating noise, they may be concerned with noise transfer.

Generally, rolling-element bearings are noisier than fluid-film bearings. Minor inaccuracies in rollers or raceways can generate sounds that are amplified by the machine structure. Improving bearing quality can reduce this effect.

Fluid-film bearings under steady radial load generally do not produce noise. However, if this type of bearing is reversed frequently, it can generate considerable noise if it doesn't have enough lubricant to fill the bearing. Fluid-film bearings running unstable in a whirling mode can also produce noise.