Impulse noise refers to sudden and high-amplitude noise that can disrupt audio or video signals, often characterized by sharp spikes that can affect the quality of the transmission. This type of noise is most commonly caused by external factors that introduce intermittent spikes or surges into electrical systems.
External power sources can induce this type of noise due to fluctuations in power supply, such as when heavy machinery operates or when electrical storms cause electrical disturbances. Improperly grounded equipment can also lead to impulse noise; if equipment isn't grounded correctly, it can pick up stray voltages or noise from the environment, which can manifest as impulse noise in AV systems.
Choosing "all of the above" signifies an understanding that impulse noise can stem from multiple sources, including both external power disturbances and issues related to grounding. Consequently, this option encompasses the broader range of potential causes, providing a comprehensive view of the problem. By acknowledging that both external power sources and grounding issues contribute to impulse noise, it highlights the importance of proper installation and environment management to minimize such interference in AV systems.