1. Noise or static on a phone line that can interfere with modem communications. Line noise is not always audible. Line noise can be inside or outside of your facility but that located or sourced outside can only be corrected by your phone company (Telco). Bad connections or loose connections are the normal cause of noise inside a user's facility. The term noise is associated with interference.
2. Noise or static on an electrical line or network line; can cause the system to lock up or crash. Some electrical line filters trap this kind of interference.