Impact noise happens when objects hit a hard surface, such as when they are dropped from height or when they hit against another object.

The noise levels created depend on the:

• size of the contacting material
• type of the contacting material
• weight of the object that is being dropped 
• speed of the object that is being dropped.

The vibration of the impact noise can also cause sound to travel through ceilings and walls.

How can you reduce impact noise?

An example of impact noise is noise generated from objects dropping onto a conveyor belt.

Other ways you can reduce impact noise are:

• replacing parallel metal rollers with a continuous belt
• using floor mats or insulation such as carpet to reduce impact of objects that fall off the conveyor belt
• cleaning belt components such as bearings regularly. Dust and dirt trapped inside bearings can create squealing or crackling type noises.

Other noise sources to consider include:

• worn and damaged belts
• the tension of the belt. If the belt is too tight, or too loose, it may create unwanted noise when the belt is moving at high speed
• the material the belt is constructed from. Adding a damping layer can reduce vibration and noise
• reflected noise from the conveyor. Line floor, walls and ceiling with sound absorbent materials to reduce reflected noise.