- noun a general level of noise which is always there in the environment
- noun noise which is present along with the required signal
- The noise present in any given environment, especially that within which tests or observations are taking place. Such noise includes nearby and distant sources. Also called ambient noise, room noise, site noise, environmental noise, or local noise.
- electrical noise which is inherent in a circuit, device, component, piece of equipment, or system. In sound recording or reproduction, for instance, it is the residual noise in the absence of a signal. Also called ground noise (3).