Error concealment is a technique used in signal processing that aims to minimize the deterioration of signals caused by missing data, called packet loss. A signal is a message sent from a transmitter to a receiver in multiple small packets. Packet loss occurs when these packets are misdirected, delayed, resequenced, or corrupted.

When error recovery occurs at the receiving end of the signal, it is receiver-based. These techniques focus on correcting corrupted or missing data.

Preliminary attempts at receiver-based error concealment involved packet repetition, replacing lost packets with copies of previously received packets. This function is computationally simple and is performed by a device on the receiver end called a "drop-out compensator".

When this technique is used, if a packet is lost, its entries are replaced with 0s.

Interpolation involves making educated guesses about the nature of a missing packet. For example, by following speech patterns in audio or faces in video.

Data buffers are used for temporarily storing data while waiting for delayed packets to arrive. They are common in web browser loading bars and video applications, like YouTube.

Rather than attempting to recover lost packets, other techniques involve anticipating data loss, manipulating the data prior to transmission.

The simplest transmitter-based technique is retransmission, sending the message multiple times. Although this idea is simple, because of the extra time required to send multiple signals, this technique is incapable of supporting real-time applications.