dropout (DO)

A dropout is a momentary signal or synchronization failure that causes errors. Dropouts are defined as random, unexpected level changeswhen the signal level drops by at least 12 dB for more than 4 ms.

In magnetic storage media, dropouts can be caused by imperfections in the coating, dust, dirt, or mechanical damage to the magnetic tapes, resulting in data loss.

Indigital recording technology, there are dropout compensators that calculate and insert the faulty information. In analog video recording, dropouts are compensated by replacing the erroneous video line with the previous line that is buffered. Since two consecutive lines differ only slightly, the dropout can be compensated by repeating one line.