Which of the following is a common source of over-the-air ingress?

Over-the-air ingress typically refers to unwanted signals that interfere with the desired signals in a communication system. Strong over-the-air television channels can be a significant source of ingress because they emit powerful signals that can enter other systems, especially those operating in nearby frequency bands. This can generate interference that disrupts data transmission or reduces the quality of service for the affected systems, such as cable or satellite broadcasts.

In contrast, digital audio signals, satellite communications interference, and USB interface noise do not usually contribute to the ingress issues associated with over-the-air signals to the same extent. Digital audio signals are typically contained within specific audio systems and are not broadcasted over the air in a fashion that affects other systems extensively. Satellite communications are designed to be robust against interference but are not a typical source of over-the-air ingress in terrestrial applications. USB interface noise is localized to the equipment using USB and does not pertain to over-the-air signal interference at all.