A phenomenon, such as damped oscillations or a voltage or current surge, that occurs in an electrical system following a sudden change in the dynamic conditions of the system and that is usually relatively short-lived. A transient may be caused by the application of an impulse voltage or current to the system or by the application or removal of a driving force. The nature of the transient is a function of the system itself but the magnitude depends on the magnitude of the impulse or the driving force.

The transient response of an electronic device, such as an amplifier, is the change in output that occurs as a result of a specific sudden change in the input.