In the digital transmission of analog signals, including analog television and digital audio broadcasting (DAB,) a signal-quality effect in which the decoded analog signal is either essentially flawless or totally unusable; i.e., it exhibits no gradual degradation or improvement attributable to the presence or absence of transient phenomena such as amplitude variations that may occur during transmission. Note: The cliff effect arises from the fact that analog variations in the intensity of the detected digital have no perceptible effect on the decoded analog signal; the only criterion for declaration of a digital mark is that the digital signal level is at or exceeds the decision level. The analog signal is then recovered without perceptible degradation. If the detection threshold is not met or exceeded, there will be no digital marks declared and the analog signal represented by them cannot be decoded, and will be lost entirely.